SDA dismantled and all the key work cleaned over three evenings (6-8 hours work). I don't mind the nickel key wear down to brass here and there, shows someone has played and played it.
From the amount of grime I'd guess it's never been apart before. The unchewed screw heads are a clue too.
Now with Paul Carrington for total overhaul, keeping the original screw in resos, apart from one missing one which he'll fabricate to match.