George, I know you like to use Isophthalic resin when doing your glass layups so is there a reason why you used epoxy to glass your plug? Would you use the polyester if it wasn't a plug but a finished part?.
My Ziroli Panther is all strip planked. Its my first all wood build in quite awhile and I am liking it. I learned a long time ago that any glue line will be much harder then the surrounding balsa so when doing the planking I used medium CA on the former's and Titebond (alphatic resin) on the plank edges. I worked in small area's and immediately took the 80 grit to the area to smooth it out before the Titebond dried. That way I was able to fully glue the strips without the dreaded hard glue line that only gets worse the more you sand it. I too remember the days before "Hot Stuff" came out. How did we ever get anything done back then.
Dean