It seems as if your major issue is paint... I've been fooling with these cars since my first one in 92/93 (It's been a while so it's hard to remember).
Anyway, I've gone through a few of them and I've always been hung up on having a nice appearance. In retrospect, I think it was a mistake. Don't get me wrong, a beautiful paint job and perfect interior is a fine thing to have (my current cars are both near perfect) but, there is something to be said for a "bucket" as the "boss" and I refer to a few cars we've owned.
I'm here because I love Turbo Buicks. It's been a love affair from the beginning. That being said, my near perfect cars rarely leave the garage. They only come out in perfect weather. Neither has seen water in over 9 years! They're garage queens and sort of a hassle. We did have another Buick once. It was a "bucket". It had rust, terrible peeling, chipping paint and torn up, faded purple window tint. We drove it everywhere- even to the grocery store! No one ever gave it a second look. I never worried about dents, dings, scratches, or even thieves. It was a true joy. It is the Only car we regret selling.
IMHO you have the perfect car! The paint is worn and the color is such that it doesn't attract any attention. I say, get the basics handled so you don't blow it up and then play around with making it reliably faster. Some Alky or E-85 will surely wake her up. Drive the car and enjoy it. If you're still on the fence next summer, then consider parting with her. (Hell, pm me and maybe we can work out a trade. I always wanted a blue TR)
Good Luck.