I will warn you right up front that this does not represent a perfect answer to all questions, but as MGA accessories go, this is about as close as it commonly gets. Perhaps it will serve to show how the quest for concours perfection can get a a bit carried away.

The factory original ones had black painted base and chrome top (from descriptin in the Service Parts List).

At 11:13 AM 12/7/04 -0800, David Breneman wrote:
>"--- WSpohn4@aol.com wrote:
>How many screws does your ashtray have? 2 or 4?
>
>".... As I recall, it has a metal strap that runs horizontally across the base, about 1/3 of the way down from the hinge, with two screws in it."

Then at 12:15 PM 12/7/04 -0800, Kelvin Dodd from Moss Motors wrote:
>"AAAAAAAAAAACCCCCCKKKKKKKKKK!!!!!!!!
>
>We are talking about a factory option which was not documented in factory records. Even Clausager hmms and hahs about whether the 2 screw or 4 screw was correct for which cars. The two screw is shown with 'The type shown here MAY only be correct for early 1500 models.'
>
>The original ashtray was sourced by the factory from Wilmot Breedan, a company that supplied many items for MG and BMC.
>
>The 4 screw ashtray was superceded by Wilmot Breedan at some time (undocumented) to the two screw design which does not have exposed screw heads. The two screw design was the type installed in many early MGBs, which indicates to me, that Clausager may be incorrect about it being an earlier design. Maybe not, none of us is perfect.
>
>Moss Motors sources the supplied part number 241-000 from Weston Body Hardware Limited in the UK, which used to be Wilmot Breedan. The supplied part is the closest in actual lineage, design and look to anything that can be supplied on the market. If you were to walk into a hypothetical MG dealership today and ask for an ashtray for your MGA, it is the part that you would be handed.
>
>The MGA catalog is getting changed to read: 'ASHTRAY, similar to original factory option.' - Similar differentiates it from being a Velcro attached bag which may be purchased from a local auto parts shop. - I'll add notes to the web page regarding the difference between 4 screw and 2 screw. - Next?
>
>This is going to sound very lame. But one of the reasons Moss has such a liberal return policy is that it is impossible to keep completely on top of all the changes, quality issues and substitutes that become evident in a 30 year old market and meet customers expectations at all times. Moss has two strong goals. 1. Not to misrepresent what is sold. 2. Not to go out of business by incurring un-absorbable operating costs. That's a fine line to balance.
>
>Kelvin"

Then at 02:14 PM 12/7/04 -0500, Bill Spohn wrote to asked me:
>"There are 2 base styles, with and without an external mounting flange, and there are chrome and black covers. I think that the MGA had chrome covers and the external base style, and Clausager seems to agree. Moss sells the non-external mount in chrome and the external mount in black crackle finish. Neither of these seems to suit the MGA. Their book shows Midget in external base, but I don't know what cover is used. Do you have any thoughts on all this?"

Yes. I'm thinking "Why should I have to be the arbiter?" I'm no concours nut. I just like to drive the things. I do not have a difinitive answer, but I do have thoughts on the subject.

Although Clausager is the oft-quoted authority on MGA, there are some mistakes in the book, and even more omissions of detail. Due to the limited physical size of the book, it would be impossible for it to cover every possible variation of production. I have a gut feeling that the optional ashtry may not have been a static design, and it is possible that variations of it may have been provided during seven years of production. It may well at various times have had any combination of the noted features.

I do not know if the optional ashtray was ever installed at the factory, except possibly on special order (speculation). It would always have been available as a dealer installed option. Dealers may at times have procured it from the MG factory source. Dealers would also have had the option of procuring an aftermarket ashtray from virtually any other source in the world. The end customers could also buy and install an ashtray from any source.

With due diligence and sufficient research, one might (maybe) ultimately be able to determine what style of ashtray may have been supplied by the factory on any given calendar date. If this were ever to be well defined, it might hold some weight in concours judging. Considering float time between original factory purchase and inventory, and shipping by the factory, and static stock time on a dealer shelf before installation in a customer car, any particular style of ashtray might be a proper part for any car produced after that style ashtray was first produced.

Until such time that this might be firmly resolved and perfectly documented, it is my humble opinion that any ashtray that looks like a proper period accessory (factory or aftermarket) would be correct for the MGA. The person who wants to claim that his ashtray is correct and some other one is not will have to do the unimpeachable research to prove exactly what was provided by the factory on any given date throughout production and for a few years after production of the MGA ceased. Anyone who cannot produce such documentation can go suck an egg, as they would only be blowing hot air. Furthermore, the only way to prove that the current Moss offering is not a correct period accessory would be to prove that this precise combination of features was never produced by anyone during that period.

Hey, it's an accessory for crying out loud. By definition, anything produced before, during or after production of the car could have been installed by a dealer or by any service shop or by a car owner. With that concept, there is no such thing as an improper ashtray in the MGA (unless personal opinion calls the accessory ugly). $.02   The floor is now open to discussion.

Addendum June 13, 2013:
Some additional pictures, supplied by Paul McKinsey:
First more of the 2-screw base unit with plain flange. Click for larger pictures.

Now a the wide flange 4-screw unit:

Addendum, November 5, 2013:
On 11/5/2013, Shaun Baker in the UK wrote:
"I have found a new old stock item, boxed AHH5539, same number as the parts illustration, but slightly different. There is a spring mechanism at the rear to hold the lid shut or open, which I have never seen on this type of ash tray".


Here is one found at an autojumble. It was exactly the same as the original ashtray, only the lid was painted instead of chromed and it had a black crackle finish.