My grandfather has a 1928 Farmall Regular. It is indeed a fine machine. The tractor you saw must have been an F-20 or it was made in another year like Skip said. They are very similar tractors. We take parts from an old F20 that my granddad bought to part out a few years ago. The regular has a hand brake while the F20 has two foot brakes. Most of the parts from the F20 will fit the regular though. I suppose that if you can find horse power ratings for an F20, they should be similar to a regular. If you are thinking about buying an F20 or a regular i suggest you do. My grandfather has used both extensively on the farm and has praised them often. good luck.