The C&C custom shop was and is Bruckmann's www.bruckmannyachts.com they are still in business, they built many of the larger C&C yachts. All the 61's, 48's and introductory models were built there. The boats they built were stick built, later the factory would build pan tooling for those boats that became high runners. If you can find a Bruckmann built C&C you probably have a very well built boat that can be reconfigured below if you so desire. Our friend has a 41 that is Bruckmann built, the boat shows as a new boat even though is was built in the early 80's.
The question of conversion or even rehab really needs to revolve around "new replacement cost" unless it's a matter of the heart for a certain boat. If a 35 year old 40 footer can be bought for $35k but requires another $100k to bring back to yare is it better to look at newer boats that have depreciated 30~40% in the first 5 years and can be bought for $150k, especially if it's lightly used and systems are still 80%? Or possibly the buyer wants to pay cash for the older boat and pay as they go to rehab an older boat, nothing wrong with that. Can older rehab boats be good investments? Maybe, if you chose the right boat and make upgrades and repairs that add value but it's tough to do when the market is flooded with used boats.
SJB, we have no intention of replacing the spar but we will replace standing rigging in 3 years. Our nephew works at a one of the major spar makers so I've been given ballpark pricing for budgeting for the work. Our spar is the same section used on the IOR maxi's so it's hell and gone stout and in good shape, cf is not an upgrade we have really considered but they make spars so.... Besides, we're just an old couple who putts along nice and easy, don't need that fancy cf stuff.