If you haven't already done so, spend a weekend with some fine emery paper( or a disposable nail file), a steel toothbrush, and electrical contact cleaner. Go through every single electrical connector there is, and make them bright and shiny. While you're at it, have some good quality electrical tape on hand for every place that a wire rubs on anything else, and a package of various-sized wire looms and ties to bundle all of it back where it belongs when you're done. You are likely to be amazed at how many problems will go away! This is a great car--mine had well over 600,000 miles on it and still ran very well when we gave it away (terminal ugliness due to body rot, because I didn't know the following).
When warm weather rolls around again, clean the underside and inner rustprone panels thoroughly, let it dry in the hot sun, and then spray everything that doesn't show with raw--repeat, RAW--linseed oil, as a rust preventative. Enjoy!
Bru
p.s. need a taillight assembly missing the usual white backup light panel? Got one somewhere in the garage still.