The ravages of time?

OK All,

So I've been 'round and 'round trying to figure out the right glider
to buy (all year). I'm sure you all are getting tired of me by now! :-
P

But I have a related question for you (for once that does not involve
a "Which glider is better" question):

How detrimental to performance are the effects of time on a glider?
I'm talking about things like roughened gelcoat, flat-spots on the
wing-skin by the spar-caps, etc. Do you think they affect flapped
gliders any differently than standard-class gliders?

(In case it makes a difference, I'm specifically concerned about 20
year old aircraft manufactured in the mid-to-late-80's)

Also, every time I get close to buying a glider of this vintage, I
start considering the fact that it will be the biggest purchase by far
in my life at this point - and seeing aging gelcoat, surface corrosion
on metal bits, worn-out cockpit interiors, etc makes me get cold
feet. Am I just being a wuss and overreacting? I'm usually not one
to dwell on appearances - but the sheer dollar amounts, and the fact
that skin-friction-drag is important, make me jumpy with gliders....

Any thoughts?

Thanks, take care,

--Noel
P.S. For the record, I found a late-90's SZD-55 in great shape that I
would have bought, but I am just a bit too tall to fit comfortably...
Argh!