Fitting new hammers to the Brinsmead action. Very unusually, this piano has mahogany shanks – most piano makers use hornbeam for this part.
I’m assuming Brinsmead decided to use mahogany as it’s a little lighter than hornbeam, and would result in an action that responds slightly better to being played quietly – however, it certainly isn’t as robust. (I also noted there is a lot of mahogany in the rest of the piano too, so it could simply be that Brinsmead was making use of the materials he had to hand!)