I found a little more info, not much, on the H&A name.
This from Charles Carders book on Hopkins & Allen Single Shots (1995).
Marlin owned the H&A name till after WW2 having bought the bankrupt company in full in 1921.
Marlin sold the name to George Numrich in the latter 40's.
After (George) Numrich owned the name and had built and imported M/L with that name including the underhammer, it was sold to a fellow by the name of Hank Goodman.
No mention of a date.
Goodman was from NJ. He imported and sold M/L and parts with the H&A name on them.
Carder does not mention the 'Challenger' brand. He only states that Goodman imported under the H&A name.
That's where my info is different (see above post), but it all came to me from a few others involved in Single Shots,,so I can't fault it. Just part of the puzzle I guess.
Carder does not list any additional owners of the H&A name other than Goodman and the present owner,,,Erwin Fagel of Indiana who mfg's M/L rifles.
This is the Deer Creek Muzzle Loader company(?) I'm guessing,,I called it Deer Run before and believe it's actually Deer Creek.
Again, no date of the transfer of ownership
No mention of Mt.Vernon or Maine bbl addresses,Challenger or 'H&A Improved ' markings,,,but some additional info to store away.
Good for somethin' even if you never use it!