I happen to have the rudder off my 1970 Columbia 26 MKII right now for a little rehab work. If you want, I would be happy to send you the dimensions, pictures and even cut a template for you that I can mail. Let me know.
Thank you for answering my post.....I wasn't sure idd this right. I would appreciate any and all the help I can get! I look forward to getting the information and your help.