Crumar T1 Organ repair help? Dead Notes

[outoftune]

I have a client who has brought in a Crumar T1 vintage organ. Unit was fully dead, I rebuilt the PSU and have the organ running again. Full cleaning of pots and switches has brought most of it back, but there are a couple of dead notes I'd like to try to fix. Does anyone have experience repairing one of these or know what might be causing the issue with certain dead notes?

A copy of the schematic is available here: https://modwiggler.com/forum/download/file.php?id=124182&sid=b44cbaf9902d034c5646b385308add2b

 

[Voyager10]

Starting with the key switches themselves is the most obvious thing. Often some gunk on the contacts, or some metal spring bent out of shape.

Can you figure out how to detach a key cap, and post a picture of what's underneath? The schematic isn't exactly clear as crystal.