OK, action is now in pieces on my dining room table. Here is what I found:
1. Whippens - I swung the whippens along their mounting point and found no resistance. I unclipped the spring - free movement in the the rest of the mechanism. So far so good.
2. Key bushings - they are new. One sticky key that I need to adjust, everything else seems normal.
3. Hammer shanks and flanges - omg! I get no swings out of the middle C and other closeby hammers. I get five swings out of the bottom (A), and about three or four out of the top treble. There is no discoloration of the wood, so I suspect it is a pin/bushing issue. So I don't suspect verdigris.
I've seen the You-Tube video of doing this job correctly. I just want to go over the steps one more time, and hope to get some clarification:
a) when you pull through the bushing cloth, you are pulling it as far as it goes, i.e. you are basically filling the entire holes with fabric.
b) is cold Hide acceptable? I hear one person is even just using Elemer's white school glue or something like that. I don't really want to spend $100 on a glue heater.
c) so basic relationship is as such: The inside determines the pin size (i.e. so it does not wander). In many cases the inside is the shank, in my Yamaha's case the inside is the attachment to the rail, i.e. the flange.
d) the outside, i.e. where the cloth bushings are, determine the friction and swing. I.e. the most important two elements are to (1) find a pin that won't wander and stays solidly in the flange (with Yamaha, the inside is the flange), and (2) using the right tool set, which I have ordered, to bore a hole into the cloth in the outer holes to achieve just the right friction. And - I am looking for about 9 swings on the bottom, heavier hammers, 7 in the middle, and about 5 on the top.
And - I get to become a real expert, because I GET TO DO THIS 88 TIMES!

(p.s. I am an economist by profession...)