On 5/5/2010, Steve Johnson in Erie, Pennsylvania wrote:
"Recently I wrote to the Denis Ferranti Laminations Company in the UK to see if they still held any archival records for the MGA fiberglass hardtop, in an effort to better understand what types of rubber seals were used originally. I recently received the reply. Unfortunately no records exist, but his reply is interesting nevertheless". -- Steve Johnson.

Dear Steve, your letter addressed to an "unknown company" has landed on my desk ---- I am Consultant Manager for Denis Ferranti Laminations Ltd of Bangor N Wales, UK [formed 1951 & STILL in existence.
When I joined DFL in 1964 we were working on MGB Hardtops under contract to MG, of Abingdon. At that time all MGA surplus parts were scrapped, the same happened to surplus MGB, MGC, Sprite & Midget parts 2 years after the Abingdon plant closed. All MG rubbers & seals were of special design by MG, and primarily manufactured under contract by Miles Redfern Ltd of Dunstable, Bedfordshire UK My notebook tells me this was a "LOUSY FIRM" !!!! that is, we had no end of difficulty getting correct supplies from them on time.
I've phoned around my local classic car club [I run a Triumph Stag, Spitfire IV & Herald Convertible] & NONE of the 3 MGA owners have a hardtop. However, from my own recollection the Factory MGAs had a reputation for body alignment being poor -- resulting in every soft top & hardtop having to be individually "tweaked" so it would fit. Indeed, this problem of poor body alignment [especially due to windscreen fit] was standard on the MGB until the last 3 years when I took them a special jig to use at Abingdon to align the A & B posts & windscreen [in order that complaints of poor fitting hardtops would stop [don't blame the top; blame the assembly methods & workforce....]
I did try to obtain both MGA & B rubbers for another American some 7 years ago [a friend of Mr de Ferranti's [who also has a large classic car collection] without success. This resulted in standard "off the shelf" rubber sourced in the States being used. Mostly this was rectangular hollow sections [top to body] & tubular hollow sections [door frame]. I've used similar on my Stag, with a good result.
No doubt you have already tried the various MGA clubs, but why not the huge MGB club ? lots of MGA owners also have an MGB & you may well have success through this club.
Best regards
Brian