On 26 March 2010, Lindsay Sampford in Cambridgeshire, United Kingdom, wrote:
"My original starter switch, probably the one that left the factory with the car, was working OK but the rubber insulators on the terminals were decomposing and allowing the terminals to move about a bit. I was worried that they might move enough to short out on the casing and cause a fire, so I decided to change the switch. I went for one of the starter switches that turn up on eBay for about £19, see image. The first one I received started the car three times before it packed up altogether! The vendor sent me a replacement without any fuss, but although it worked, it wasn't very convincing in the way it worked, if you get what I mean. It took a good hard pull to get the starter to turn with enough oomph to start the engine. Although the thing has worked for a year it has got steadily worse, and it has been a real struggle to get the car to start at all on the colder days.

So I have replaced the stater switch again, this time for one that looks more like the original. It has the same rubber insulators as the original switch, seems much more robust and starts the car in a very business-like fashion. At around £25 inc. vat. it cost a bit more than the nylon based version, but well worth it. The cheapest one I was able to find came from Vintage Supplies in the UK -- Part No. 945

Applications: MGTD, MGTF, MGA, AH Sprite MKI-II, MG Midget MK-I, Austin A30 A40 A50 A55. Metropolitan, Morris Minor (to 1964)
Also some models of Jaguar, Hillman, Singer, Allard, Triumph, Nuffield tractor.

BMC                3H949
Unipart            3H949
Lucas type ST19    76423A

Moss Motors USA    145-800
Victoria British   8-574
Vintage Supplies   945
Ford               ET6-11450-B - 300E 5cwt & 7cwt Van (1954-1961)
                               - 100E Escort & Squire (1955-1961)
                               - 100E Prefect (1953 - 1962)

Addendum November 1, 2021:
Here is one I bought from Scarborough Faire (just because I wasn't about to buy another junk one from Moss Motors USA). No markings at all on the part or packaging, other than the vendor's inventory number, so no telling where it came from.

The power posts appear to be copper (not sure yet if solid or only copper plated). I haven't checked the thread type yet, so try not to lose the nuts. Pull action seems straight and smooth, no hitch or wobble, and not excessively hard to pull right at end of travel, so that's somewhat assuring. This one is for spare, so I don't know when I might get to try it out in service.

Addendum April 17, 2022:
Now we have another new part for consideration. This one was found on eBay-UK, so for as long as the link may last, see here: https://www.ebay.co.uk/itm/193505805851
The green box and Lucas name does not impress me, as these days the name is franchised, so anyone who will pay the license fee can put the name on anything (good or bad). I have not touched one of this particular part (yet), so no personal opinion or facts available (yet), only some observations based on the pictures. At least the mounting nut looks thick enough to not strip the threads during installation. Packaging date appears to be mid 2020.


The threaded power connection studs have me somewhat concerned, as they appear to be "not copper or brass", where original studs were copper for best electrical contact and conductivity. No telling from pictures if the power studs are keyed for anti-rotation, or if the threaded mounting collar is keyed or properly secured for anti-rotation. No telling if the internal contact plates are copper or not until someone might disassemble one for inspection. Same comment for the internal structure between the pull rod and insulators and moving contact plate and spring, etc, all of which have been problems in other recent aftermarket "cheap" parts.
Now we get to wait for a user report and some time in service to see this one holds up better than many of the junk parts recently on the market. So if anyone has recently installed one from this new source, please send photos and notes to let us know how it works out.

In reference to the switch noted above, .... On 4/26/2022, Mark Hester wrote:
"I had to finish off the 3/8 UNF threading with a die nut. Also the thread is about 1/4 shorter. Seemed good UNF on the central barrel. I swapped over to my 3/8 half nuts okay, other than the central barrel was a bit short, so little adjustment --- Alas not keyed or secure, you can turn the whole thing and possibly earth it out if not careful. I used a 5/16 spanner so assume the terminal studs are not metric".