This whole thing with resale value makes no sense to me. If you try to keep SC resale values high by paying more for SCs ... you will not come out ahead. You may get more for your car if you sell it, but you will have already paid more for it in the first place. And chances are that you will spend more than you save because it has depreciated in the meantime due to usage. Plus, SCCOA members are a drop in the bucket compared to the number of SC owners.
And the low resale value is due to dozens of factors. First, few people see them as performance cars. Second, they are complicated and difficult to fix (10lbs of car parts in a 5lb bag). Most mechanics don't know them well, and many don't even know they are rear-wheel drive. Or have an independent rear suspension. Or have control arms at all 4 corners. Or know how to align them. Third, parts for the SC are unique, expensive, and hard to find. MN12 parts support in general is spotty and probably getting worse. Try buying body parts from Ford - only an oil baron can afford that stuff.
My point is that, despite what we would like to see happening in the world of classic MN12s, we are a small group, and are therefore at the mercy of the larger trends in America.
If a wealthy club member steps up and buys/leases/makes tooling to keep body parts in production, I think we will be in good shape. If things keep getting discontinued at the rate they are now, it will be a dog-eat-dog world before long.
But if most of the SCs get crushed, the remaining ones will be sure-fire classics, with excellent resale value.