Yes, there was only one Beaver II (MSN 80), though confusingly it wore two different UK military serials at different times.
The fin/rudder was certainly bigger then the Mk I Beaver. I can't comment on the direction of rotation (other than to observe that usually British and US radials rotated in opposite directions), nor on any fin offset.
Edit: Forgot to add that the Beaver II is still flying from Flin Flon in Canada, albeit now re-engined with a PZL-3S (Polish licence-built Ivchenko AI-26).
Last edited by DaveReidUK; 12th Jan 2022 at 14:35.