76 Grampian 28?
I have a 1968 Grampian 26 that I bought 3 years ago and have sailed extensively since then. This boat had a completely new electrical system installed by the previous owner, as well as an Imron paint job, custom SS bow pulpit and teak anchor platform. The interior was stripped down to the bare plywoood, and I completely rebuilt it, using mahogany plywood and solid mahogany and fir.
I have made many upgrades both in the interior and on deck.
This is a solid, well-built boat. There are no deck leaks, no soft spots or delaminated areas, or blisters. The Grampian 26 is surprisingly fast under sail, and with it''s heavy ballast/displacement ratio, it is stiff and does not require reefing until it really blows. My wife and I, along with her teenage daughter, cruised on this boat for 4 months last winter. We had no boat-related problems.
As to age, and whether or not old boats like this "wear out", I recommend you read Don Casey''s book THIS OLD BOAT. Lots of info in there on refurbishing and on the sensiblility of buying an old boat.