Years ago on greedBay I won a couple of all brass (including the shackels)
Corbin padlocks. On the reverse of the lock bodys near the top are small
indented Ford scripts. On the locks bottom I can just make out '07 and '09 patent dates. Most likely the locks are newer then that, but they
both came with keys, one of them being an original Corbin. Henry probably had thousands of them made for all his different interprises.
Ford didn't supply the postal truck bodies. They came from a few different contractors. The postal garages mounted the bodies to the ford supplied chassis, inturn they used Post Office Department locks.