There was a slew of Pennabackers/Pennybackers, along with various spellings.
Generally, the name on the bottom of the barrel would indicate the barrel maker, and not the gun maker.
And I agree with the comments at the bottom of the picture page, that it was originally a percussion, with this flint contraption wishful thinking. The style of the stock is late, a single bolt lock, and much wood burning around the tang area and ahead of the frizzen.
Otherwise, just consider it an example of an every day gun that some ol' guy used and no doubt cherished.
John
