Thanks sparky and David!
Yes the bench will be a good addition to my shop. It has already proven to be the right size to stay put even if it is not fastened to the floor as I planed some wood the other day.
The hammers, yes, I took a new picture from the head end to show how I did:
The carvers mallet handle goes right through and is 20 mm dia as stated earlier. Glued with epoxy and uses a standard wedge to secure. It should stay in place.
The hammer is done in the same way. Nice fit and epoxy + wedge. the rough inner walls will make the glue stick well.
Hope this helps.