Right side thumb strap on English concertina detatched.

[d.elliott]

I cannot remember on the Morse, if there is a central long screw going down a pillar into the pad board or not. 

 

On traditional instruments, this is the case on thumb strap plates and finger slides. Please remember that the hole down the pillar is a clearance hole to the screw, the pillar is a spacer to prevent damage to fretting, hence the packers between the pillar top and the underside of the fretting to make a firm 'sandwich'. The long screw transmits the forces of play from the thumb strap/ finger slide through to the action assembly without any stresses being applied to the delicate fretwork. It is the tip of the long screw that bites into the action plate wood that does the work.