Piano Action Parts Kit

Description

This kit was passed along to me by a relative who at one time in the mid 1980's thought he wanted to learn how to tune pianos as a side business. He purchased a training course and all the necessary kits, changed his mind eventually and put the items in climate controlled storage. Now I have them and I'm downsizing and need to get this kit to a new home. You'll have to assess this kit and contents from the photographs. I don't know anything about piano parts to answer any questions.
The heavy-duty plastic carrying case itself measures 18" wide x 12" high x 12" deep. I have laid out the 28 items that are in the yellow compartment. There are also two additional parts drawers below the yellow section, and I have shown the contents of each drawer. My relative put labels in most of the compartments, no doubt to aid him during the training process. The items look unused and in pristine condition.
I believe these parts are for a Yahama piano.
I am no expert, however, and can't verify my belief.
My relative had a Yamaha baby grand, and also purchased a tuning scope for Yahama pianos, so I'm making an assumption based on those facts.