loose hammer heads

[Clyde Hollinger]

Friends,

Today I tuned a school piano, a Yamaha studio model P22, or whatever
model they called it when it was new back in 1971.  It has many loose
hammer heads.  How would you recommend I reglue these?

In pianos where there are just one or two loose, I generally just work
it off and reglue.  Is there danger in breaking the butt or flange by
doing this?  I think I've heard of turning the action upside down and
using the water-thin CA on the loose ones.  I've never done that.
Advice?

Regards, Clyde