What you can't tell from the photo is how small they are - you could easily fit all five on top of a 50p coin.
Here they are after turning up new caps for them and polishing them, alongside a good original button for comparison (not all of them are as perfectly round and smooth as that one):
The photo really emphasizes the difference in appearance between highly-polished stainless steel and nickel silver. It isn't normally that obvious to the naked eye.
Time spent so far on the restoration, not including research and ordering parts: about six hours.
I've been practising playing it for a few minutes two or three times a day, apart from when I had it in bits to fix the buttons. Just this morning I managed to play the first tune in my tutor book (Winster Gallop) all the way through in one go, albeit quite badly. It's quite an amazing feeling when you first make that transition from producing a disjointed collection of notes to playing an actual recognisable tune!