I have one as do two other guys on my pier. The hulls were laid up by hand and by all accounts, very tough. Ours is a 1977 and no issues. The other two are both 1978's I believe. Neither has any problems that I am aware of.
Tom is correct, they were built in New Orleans
by a guy named Mike Brenner, I believe, in the 1970's. He has since passed away, but is still spoken about with great respect.
I have been restoring it for the last two years so I can probably help you out a little if you decide to buy. I think you're right on building the interior
yourself. I probably would have been better off doing it that way and getting the exact interior I wanted. I think any E-38 owner would recommend the boat.
I have seen various configurations so I may be able to tell you some things that work and some that don't.