Thanks for the replies!
The cam looks new to me, like its coated in a rust preventer. Didn't see any wear marks.
Muffler is too small for a 110 Deere--at least the early (mid 60's models)--dad has one
Maybe Deere changed the design in the late 60's early 70's?
The 128 here has the same, long round silver muffler that is on my 124--about the size of what is on a Farmall Cub with a shorter pipe (and side inlet).
Got some other new sheet metal and valves--I'll try to take pics.