Hi, it's me again!
I was playing some piano at my grandma's today, as I wanted to record some YouTube videos and she has the best feeling and best sounding piano I've ever played on.
I just now realised it has 85 instead of 88 keys.
I don't know how I didn't realise this before :P
It's never been a problem, though, I've never played something that needs keys that high.
What keys are missing?
It would be the top three; B flat, B natural, and C.
Most pianos pre- 1900 were like this, and thus, most repertoire is written from the A - A range (which really makes more sense logically speaking).
Unless you're specializing in 20th century repertoire that MUST have those 3 keys, you should be fine; same deal with the sostenuto pedal, which it very well may not have.