Re: 87' Cobolt 23
I love the 23' Cobalt & made an offer on an '87 myself! That said I don't think they were all fiberglass until the late 90's.
They are really well built boats, hence the original price tag of $31k. Comparing the interior to my 88" searay 230, the Cobolt has a complete fiberglass deck, ski locker is all glass as are the cabin bunk bases, steps ect. Whats not glass is teak making for what seems to be a very long lasting boat. I suppose the stringers/bulkheads may be wooden cored, but from what I can see everything is encapsulated in glass.
Good luck on your offer,... a well kept Cobolt is a treasure to be found 4 sure!