I found my old Game Boy laying about, working semi-decently, and this thing has been passed around by a handful of previous owners... has never been opened or cleaned.
Pretty much amazed that I didn't find any sign of organic life within, apart from the dustballs, fingerfatgrease and what not, even some battery acid damage etc.
Got around to disassemble it entirely, cleaned up ALL the components, buttons and what not... fitted everything in a brand new case and replaced the screen as well. All in all, it works just as fine as it did when it left the factory.
"Finished" product can be found here
There will be some hardware mods on this thing later