Grampian was a very early fiberglass boat builder. I actually owned one of their boats from the mid 1960''s. In the mid 1960''s they were considered to be a reasonably high quality company. In the late 1960''s Grampian retooled its
line coming out with boats that were highly budget oriented and not very well built. Compared to their earlier boats this new
line had little to recommend it except inexpensive pricing and a lot of room for a 30 footer. The Grampian 30 that I knew best was really pretty shodily constructed and was a mediocre sailor at best. Grampian was one of the last companies to use extensively plastic laminate (formica) over plywood. While plastic laminate is easy to wipe down it allows the substrate to rot out undetected.
Comparing the build quality of the Grampian 30 to the Hunter 30 of that era, the Hunter was much better constructed and finished and was a faster and more easily handled boat.
The real issue with the poorer constucted boats of that day is how well they were treated over the 25 years of their existance. Did the owner replace the problem systems and upgrade hardware? Have rotted bulkheads and lightweight chainplates been replaced? have modern electronics been installed? Have they purchased new sails and replaced
rigging? And so on.
These boats originally had an Atomic 4 inboard. I don''t think that there was an outboard option. I cannot imagine installing an outboard on a Grampian 30. It would be a very big job to do correctly.
So while the Grampain 30 would be a big jump up in quality from your Magregor 25 these are still not very high quality boats and given the age of the boat, I would be very careful about buying one. Even if you bought one as a fixer upper, these boats have such low resale values even in pristine shape that unlike a higher quality boat that was down on its luck, these would be a hard boat to recover a reasonable portion of your investment at resale, especially if equipped with an outboard.
One last minor point. I believe that the Grampian 30 went out of production before 1979 but I could be wrong on that.
Respectfully,
Jeff