I see Zonie posted much the same info while I was still typing mine.
The Pennsylvania-Kentucky Rifle by Henry J. Kauffman probably has the most information on Enterprise Gun Works. He dedicates at least a page and a half to it giving the history of the various owners and illustrates some advertisements of the firm. Kauffman reprinted a section of an 1883 catalog that has some interesting information such as what Kauffman stated as the earliest record he knew of a manufacturer calling his products "Kentucky rifles". Of course we know of an earlier reference in a song about the Battle of New Orleans plus there's some unpublished research that has found the term "Kentucky rifle" used even earlier than the War of 1812. But to Kauffman's point, this is a gun manufacture using the term.
The firm started in 1848 by Bown and Tetley. An 1855 advertisement is specifically directed to people passing through Pittsburgh on their way to the newly opened West. By 1862, the firm was solely owned by James Bown. Bown subsequently brought some of his sons into the business when they came of age in the mid-1870s and in 1883.
Below is a scan of part of what Kauffman published.
The section above in the catalog where they are touting the benefits of a muzzleloader over a cartridge gun for small game hunting is interesting. The catalog also states that they made their own barrels, locks, triggers, and mountings. Of course, other large gun makers such as the Henrys and Leman did the same to one degree or another.
Kauffman doesn't give any information as to the scale of the Enterprise Gun Works production, but it was probably much smaller than Leman, Tryon, Henry, and Deringer since they specifically state they have trouble meeting the peak demand during hunting season for their rifles.
Concerning the number 130 stamped on the muzzle, it's possible that represents the number of balls to the pound that the rifle took. In the mid-1800s, England passed a law that required the bore or balls-to-the-pound be stamped on English guns, but it wasn't common for American gun makers to so mark their guns.
The best way to tell would be to slug the bore of your rifle and measure it size. A rifle that carried 130 balls-to-the-pound would have a bore size (land-to-land diameter) of .34" to .35". That includes a windage of 0.015" to 0.020". The ball itself would have a diameter of 0.330". Bore diameter equals ball diameter plus windage.
Another way to get a pretty accurate estimate of bore diameter is to use a set of go/no-go gauges. I've successfully used a set of brass cleaning jags like those shown below.
I have an antique Leman squirrel rifle. The .40 caliber jag from the set above has four rings separated by grooves like the two jags shown in picture above. The two rings closest to the male thread are 0.340" in diameter. The next ring is 0.350" diameter and the ring nearest the end is 0.360" diameter. The jag will go into the muzzle of the Leman barrel up to the end ring, so the bore diameter at the muzzle is between 0.350" and 0.360". In the period terminology, it would be about 120 balls-to-the-pound. In modern jargon, I would call it a nominal .36 caliber, though it's probably more accurately a .357 caliber. But I wouldn't call it a magnum.
Of course in the day, the numbers they used were nominal sizes. Their tolerances and/or their ability to measure accurately were probably plus or minus a hundredth of an inch. Even the process of weighing a certain number of balls to equal a pound had some error in it, depending on the type of scale used. When one is dealing with bores this small, the difference in diameter of the ball between 120 and 130 balls-to-the-pound is less than a hundredth of an inch.
