>>713531694
The Model M I got was refurbished and the only problem was the PS/2 to USB adapter. If I mash several keys at once, it can fuck up.
It "stuck" with keys like thiiiiiiiiiiiiis due to hardware differences over the decades. You should prolly get a Unicomp because I spent a good hour of research on a dead forum (2011) just to find the right adapter with 1 in stock. It was called Blue Cube or whatever.