Someone is misreading the parts book
In regards to rotors, even though the listing in the parts book can be a little confusing for 1953 it reads:
1933-52 All (except standard),1953 all with 216. #820445
The only reason 1953 is standing out by its self is because the 53 235 uses the tall rotor(as do all 1954 and later).
Are you sure you have the correct "short" cap?
