It's interesting that I hadn't actually fully memorised it, though it felt as if it was embedded last time I played it. This is subjective, but it felt as if recalling two hands working together was the difficult part - a melody alone might have been easier, but it was as if the two handed learning had overwritten the earlier RH melody learning.
Got the first seven bars back ok, and puzzled through the rest but haven't got it all back yet. Another hour should restore it to the process memory, and then I can get back to actually practising it again. Which I'm looking forward to, practising on a strange piano with its own history, it's a bit like a holiday romance.
The piano's in a big gym hall, used for dancing instruction. The sound in that big space is lovely. The keyboard feels rather more certain than the Kemble. Heavier, maybe. I can put a restored Bluthner on a list of possibilities for a retirement piano.