Some inspection of the pistol revealed that the muzzle was deeply recessed–over two inches–and the barrel was counterbored to about 0.265″ in diameter.
I discovered a 1-3/8″ diameter aluminum ball for a machine deal with within the McMaster–Carr catalog.
The ball and a 2″ lengthy 5/16″ shoulder bolt accomplished the components record.
The ball and bolt each have 1/4-20 threads.
Lower the pinnacle off the bolt…
And turned down the 5/16″ diameter to about 0.262″ to suit into the tip of the counterbore.
Did it in sections–keeping the overhand to a minimum–then polished it with a bit of maroon scotchbrite.
Head blued the shaft, then threaded it to the ball with some medium energy Loctite.
Low-cost, fast and no extra hand ache.