I've bought 2 Model As out of the US. When I received the first one, the gearbox was so dry there was just enough oil in the bottom for the big gear on the lower shaft to dip. When I asked the PO about that, he said "That might be right, I've never checked it"

. The gears were all galled but the bearings ran quiet so I flushed out the sparkly bits and refilled with my usual 250 grade transmission oil. I've done several thousand miles since and all is running well so far.

The second car had just been serviced by a current Ford dealer. WHAT A MESS. The brakes were so far out of adjustment they were dangerous

, the diff was bone dry and the Mitchell O/D only contained about 200ml (6-7 ounces) of oil.

My guess is that they didn't have the tool to undo the plugs with the square holes so they left them. I drained, flushed and refilled the diff. It survived

. I drained and refilled the O/D with GL5 EP gear oil and it also is OK.
The car had been "serviced" only just before it was sold (to me) and had done only 13 miles since. The sticker on the windscreen said the next service was due was 3,000 miles down the road. Must be some super oil to go that far without an oil filter. These people were IDIOTS!
I won't identify the dealer other than to say they are in AZ unless someone asks in a PM.