Battery cover from November '55 car, (c)10629. Photos courtesy of Joyce McCombie.

On 20 April 2014, Peter Tilbury in British Columbia, Canada wote:
Very early MGAs have 5 dzus fasteners in the battery cover - 2 on the sides, and 3 along the back edge. Obviously, these 3 are hard to get at with the spare wheel in place. Later cars had only 2 on the sides, and a lip was added to the rear edge of the cover so it could be slipped under the wheel".

We know that a July '56 car, chassis (VIN) number 18273, has 2 fasteners, while a November '55 car has 5. The MGA Guru would like to try to establish the approx change over date, so if your car is prior to chassis 18273, please advise if you have 5 or 2 fasteners.

Chassis no.  DATE  No of Fasteners
   10626   Nov '55	5
   10629   Nov '55	5
   10970   Dec '55	5
   12603   Mar '56	5
   13201   Mar '56	2
   14408   Apr '56	2
   18273   Jul '56	2

This is beginning to look like the first 3000 cars, possibly through 13100.