[tmodelman]

No VIN, that didn't come along until the 1960'.

The engine number is the 'serial' number on a T, and that is the registration # to use.

That number is stamped in the engine block on the left side above the water inlet port, if there is an aftermarket water pump or horn, the number may be blocked from view.

Beginning in the 1926 model year, the Improved Fords that were introduced in Aug 1925, began to get on Dec 12, 1925 a number that matched the engine number, stamped on the frame rail upper, located by the running board brace. lift the floor boards to see it...sometimes ti was stamped on the left rail, most times on the right rail.