I wouldn't care if the electronics are out of date. If they are functioning, good enough. When something breaks, you can replace then.
I love the boat. New diesel and electrical are huge plusses. Woodwork seems to be in beautiful shape. I bet the rigging and the sails are on par and kept well maintained/replaced.
Financing a boat that is above it's average market value is next to impossible though unless you put in enough down payment to make the difference and some more.
1978 Gulfstar 50'
Clark Sailing Dinghy 10'