Could be a P42 Hi po, did the clutch cover have a decal. the muffler is not correct, the1 starter cover screws match a P41 , the one flange bar nut is P42,
The Pioneer Farmsaws11also had those fibre Reeds.
From anything l have learned is that the biggest difference is the Cyl and ign used on the P41Western is the same as a regular P41.
Thats what l based my build on and Maybe after all said and done it was wrong info l collection.
Anyone like to add to this conversation , l would be intersed in hearing from you.