I was swapping the pre-amp on my little fender and I had to destroy the metal cover with the spring in it in order to remove it. I had to because for whatever reason there were big globs of glue holding it on. Does it matter if I replace it...?
i dont think it matters as much as you think. i only have my pre's half covered. i think the cover is more of a physical protection thing instead of an electrical interference thing.
If you only play at home, I wouldn't worry about it, but if you are moving it around a lot, I would buy new tube covers.