Squire was a New York lockmaker furnishing parts to the trade. I found mention of a Squire & Co lock on a P&S Remington muzzleloader, a partnership said to have lasted only one year as Philo Remington moved on to take Ephaliet's place at Remington Arms in 1861.
There is no sign of conversion from flint to percussion.
The underrib and foreend tip argue against it having been cut down from full stock.
The seller's language is sloppy, to call something a "American Revolution Musket Kentucky Rifle Antique Percussion Flintlock Civil War Revolutionary" is mashing together maybe half a dozen different categories. Few if any of which apply. I guess it could have gone to the Civil War, but would have been a handicap to the user because it did not take standard Minie balls or a bayonet.
Worn, broken, and $2000?
No.
Style a reproduction after? Sure.