I think you will spend more trying to make something look decent than you need to. Not using marine
plywood is a big mistake as regular plywood will not hold up and in a very short period of time, you will have the opportunity to learn from your mistakes
as you have to do them again. Even if you glass over it, the mat and supplies won't be as cheap
as you think. If you want a nice looking wood surround, you need to use teak
or maybe mahogany and let me just assure you (we are in the midst of a lot of teak
work) it is seriously expensive stuff. If you make a mistake in your cutting, it gets REALLY expensive.
If all you need are frames and gaskets, you would really be silly to build them yourself when Beckson sells component parts
for a very, very nice price
Beckson Marine Inc.