Oh sh*t! Its a slippery slope Ian. You'll bring it home, get used to all its quirks (gearchange etc.), then you'll want another!
If you want to drive it, then the glassfibre wings are not a problem (ALL the outer panels on my Bertone are plastic) and you can get replacements from Bob Wright at www.wrightrestorations.co.uk
. If you're a polisher and want to show the car, then un-original bits like that are bad news. It'll be marked down in concours and obviously reduce its value.
The problem with Alfetta coupes is that bodywork is expensive to fix (probably more so than for a Bertone). The inner wings, sills and wheel arches are prone to rot especially if cr*p gets down behind the front splashguards. If it has a sunroof, blocked drainage channels can cause trouble at the base of the A-pillars and early cars with chrome windscreen surrounds can rust round the screen edges.
The gear linkage can be sorted by someone who knows what they're doing, but it'll never be as good as a Bertone or a more modern Alfa. The good news is that the handling of any of the transaxle Alfas was good straight out of the box and they respond really well to tweaking. A well set-up one is great to drive.
My advice is if the body is solid and you want to enjoy driving it then you won't be disappointed. If the body isn't, or if you want a show car or investment, don't touch it.
If you think you want it, get a specialist to inspect it before you commit. Make sure you know the going rate (check out the classifieds on the AROC site) then haggle down.
If you have any doubts, wait! There'll be a better one along later.