Some pictures of my action work.
It started like this (click on the image to enlarge)
It was extremly dusty and several parts needed repairs and adjustments
Slow work of disassembling and cleaning:
Keys outside of the keyframe (for cleaning, minorly whitening and gluing the couple that were broken):
Key detail of the polished capstan with a historic surprise:
Bottom of the keyframe (note the 4 brass glides for the una corda shifting). Funny as this simple frame is one of the most expensive parts to build if you are starting from scratch!
Cleaned and (mostly but not completely) repaired:
Same neatness and tidiness when looking from the side. Boy I wish I took a picture of the "before": you could see only the first whippen, there was so much dust accumulated that everything was hidden in this view (you get a glimpse of that dust in the removal-from-keybed picture above, but that dust is nothing compared to what was here (after all, the dust there could enter only from the small space in between the keys, whereas here there are plenty of entry points):
Strike point measurements. Notice how close the back of the cabinet could be if you want to reduce the overall depth as much as possible (without changing pivot length 🤣). At such closeness, it'd be a challenge to assemble and regulate the key-release sensors, let alone any back-action simulation (weights like the dampers, removed when pedaling, a la Kawai Novus). But you could opt for hammer-only sensors (or have the key sensors under the keys a la QRS stript) and do it without the dampers-like pedalling. You can see in my video in part two I opted for a more deep cabinet, to make my life easier.
And here is the end result, cleaned, repaired (albeit not completely yet) and regulated (even though not with the final accuracy yet). Funnily, at a cursory look it does not seem much different from the first picture 🤣