Repairing plastic threads & discoloration

[blacksheeplogic]

Just wondering how others are making repairs to plastic cases.

Where the thread is too small and fine for an insert I've been using PTFE tape to create more of a bite (where it's not broken). Helps and is better than moving up in size. Any better ideas, glue I found is pretty messy for a lot of these which are very small.

I have a lot of Atari 8-bit gear, some I have re-cased, but I need to start using what I have. Hydrogen Peroxide can work in the short term but it's not good for the plastic nor is it perfect. Considering spray painting the cases now but it's never a 100% color match and I want to keep these as collectible. I'm looking at some point to downsize and maybe only keep one of my systems so collect-ability is important. I have considered selling some working systems off as parts but I'm not at the point of wanting to trash working systems.