Peroxide, heat, and UV light makes for a good combination.
But it’s not without risk, such as streaking or over-lightening. It also isn’t a permanent solution, but should buy you a good additional handful of years if the console is stored under optimal conditions.
I have used retrobriting on a few consoles, with decent results. I restored the plastic on a model 2 Japanese Sega Saturn this way, and it turned out gorgeous.
In regard to controllers, Japan auctions are an excellent source of real-deal OEM controllers in great shape. I’ve been burned so many times by fake controllers in the US, that I just buy lots of them off of buyee.jp now if I need them.