Alan- have you grown since you bought the boat?
Anyway, my decision would be based on how long I plan on keeping her ... if short-term, I wouldn't change it. Long-term? Change it.
It's not like you will destroy the value of the boat for 99% of potential buyers down the road.
I too have an old CC- 1964 Cavalier ... I have made some tasteful modifications that 'fit' the style of my boat. Heck, it's my boat, and I want it the way I want it!
It sounds like you are giving the appropriate thought and consideration to the 'challenge' at hand ... trust your instincts and heart when it comes to boats.
Brad
Nothing else matters but how I raise my children ... and their opinion of me, as a father.