If it is sort of a boxy looking tractor, and has a firewall between the fuel tank, look high up on the firewall, on the engine side, most times it is covered with grime, so take rags and solvent to clean the firewall off. If the hood, grill, and fuel tank have a rounded appearance, the tag should be on the right frame rail, on the outside, near the footrest. Most of these have been knocked off years ago, but on occasion you might find one. On this same model, there would be an engine tag on the side of the block. It won't tell great things about the tractor, but it will ID the engine. Also, on this model, there would be a casting date, month and year, on the block, these are cast into the block.
Have a great day!!!
Andy