Hi Larry
with what you have posted, you biggest concern will be keeping the aft end as light as possible, from my notes in the margin of my manual pg 12 Rudder build step one to change the top of the rudder to be more scale like I re made the AFT BASE to extend the upper curve about 1/4,if you compare pic's on a full size and what in the plans the Rudder needs to be more rounded, so vary easy if you start right. I did not care for some of the wood furnished, so I replaced it with better wood selection for the part.
Good luck with your build and Please post pic's as you go
Cheers Bob T