Assuming the First 51 is of the late 1980's era, they are excellent boats and, unless the yacht described by Erison38 suffered some extraordinary damage, his
Engineer pal is talking through his hat. The 1980's era First series yachts designed by Frers and built in
Europe were some of the best boats built by
Beneteau and considered then, and still, comparable to the Swans of the era but at half the cost. The boats were featured prominently in Ferenc Mate's acclaimed 1986 book "The Worlds Best Boats". The one drawback to the 51's is that many were delivered with
teak decking, which, by now, is aging and likely needs replacement if it hasn't been replaced already. Frankly, if I were looking at one in need of re-decking, I'd get rid of the stuff and refinish the decks without but some like the aesthetics, which is, admittedly, pleasing.
FWIW...