About the Kurz's lower half: old cover but news stickers. Can't remember where i found them.
About the 5050, you're right, it's now difficult to found one. The 5080 is better but no-usb interface and twice the 5050's price.
As you said, today there's a bunch of softsynth and i'm waiting with some fear the Korg Legacy Edition of Triton. Dunno if Korg plan to emulate the MOSS synthesis or not. It's only for MOSS capabilities that i've kept the Triton. If i find a decent Z1 i'll take it.
In the future, i think i'll sell everything, or most of keyboard except the K2000 and P120 for a Korg Oasys or an Openlabs machine (Neko76 or OMX24).
But dunno if i'll be able to sell my beloved keyboards