I have decided to sell my tuning practice piano,now that I have done all the work I'm going to do with it.

My only issue right now is on the back,where the caster is attached to a block of wood,glued to the bottom of a ridge on the soundboard,that block came loose.

The way the block is placed is between two support posts,and there were no screws attaching it.

Any one have an idea?

Add some glue and some screws.

If one of those blocks between the posts has come loose, the chances are good that the other joints have become weakened as well. Be sure to give all those joints a good visual check, and see if you can get a palette knife into any of the cracks. Re-glue as required.