GOod looking build. I too have one model kits that I've been working on forever. Was my first kit ever, a 1970 Charger I was gifted around 2007. Still not completed. Maybe this year.
As for your widshield, polish with some fine paint cutting polish/rubbing compound. Tamiya has a set of three polishes (from coarse to superfine) that works wonders at clearing up scratched or damaged old plastic.