If a complete disassembly and cleaning of the keyboard still results in sticky and non-functional keys then yes a replacement is your only option.

No NOS keyboards that I've ever seen, but CBM/PET can be found occasionally on eBay.

Apologies I don't recall their direct website, but reproduction front labels can be found on eBay as well.

FYI, I'm not an advocate for eBay and don't get me started on their Global Shipping Program, it is just that sometimes it is a necessary evil that needs to be checked.

--- SoupGate-Win32 v1.05