Triumph Repair: Spitfire Differential, filler plug, drain plug

Question
Have found the drain plug at the bottom of the differential; however, cannot locate the filler plug.  This is an early 1964 Spitfire.  Thank you.

Answer
Greg,

There is a fill plug on the right side rear mounting ear.  Look for a 7/16" square head plug.

Originally there wasn't a drain plug on the differential.   It appears a previous owner has fitted the differential with a drain plug.

Cheers,

Jim