This is a problem I've always faced, but years ago made the decision that with my crazy sentimentality and love for MY SVX, I will just stick with it and keep it running and slowly work to make it into my version of the perfect SVX, at least as long as that is somewhat practical at least.
13 years in and still other, more important, issues that would take priority before looking into the much needed bodywork and paint. I can fake it pretty good in the meantime as anyone with this year's SVX calendar will see next month.
As others have said, to take that final (and probably most expensive) step and have the exterior restored the right way, you have to be doing it for YOU and the love... it will not be "worth it" from a financial point of view, so just make sure it will be worth it from your heart's point of view.
I have been curious about something though, and maybe Armando and some others can chime in..... Is there a special way to handle insurance on one of these beauties after they've been restored to such pristine condition? I realize the resale loss aspect and could make peace with that if I knew I was keeping the car a good long time. But it would be harder to swallow putting $10K into restoring a car and a month later getting in an accident and insurance only be willing to shell out $3K for it.
That's my biggest concern at the back of my mind every time I think about this, but maybe it's not an issue at all?