I picked up a very old allis chalmers 5' finish pto mower 3pt hitch. I can find a model or serial number anywhere. One person told me it's probably a woods, and to starat there! It seems to be in 1950 range.
everytime i ask, or have seen, it has always been a "woods" mower on an allis chalmers. though do not take my word for it. just an owner, and tried searching for things in past, and what i have came across.