I believe the rifle is the same one that is shown in the Dixie Gun Works 1980 catalog.
The ad says:
PENNSYLVANIA LANCASTER COUNTY RIFLE KIT
One piece maple stock with 95% of the inletting already completed. The buttplate, toeplate and patchbox is one solid waxcast piece that is very decorative and easily assembled. The rifle is completely brass mounted with a double set trigger. The percussion lock is a fine quality lock which has a casehardened colored plate and hammer. Stress points have been hardened for durability and long life. Brass front and rear sight. Barrel is 36" long, about 7/8" octagon and is a .45 cal. Shallow groove rifling with one turn in 48"
Groove to groove diameter is .455 and land to land is .451. We recommend using a .445 patched round ball. Kit is 95 percent inletted and very easily assembled. Available in flint and percussion. The only difference in the flint is that it has the flint lock and flint barrel with a vent hole. The flint lock is a fine quality lock with a casehardened colored plate and hammer. The frizzen has been hardened and is ready for use. We know that these kits can be very easily assembled and made into a very nice looking gun that anyone would be proud to own.
The rifle is completely brass mounted with double set triggers and a fly in the tumbler. Depending on the kit that you purchase, it can become interchangeable as either flint or percussion. To change the flint rifle to percussion, simply install a 5/16 x 24 drum and nipple $(1.75) and #DGW108 percussion lock ($19.95). Swap the flint lock for the percussion and replace the vent with a drum and nipple.
If you have the percussion kit and wish to make it a flint, simply remove the drum and nipple and install the 5/16 x 24 vent and replace the percussion lock with #DGW107 flintlock ($24.95).
If you prefer, the other lock and parts can be purchased at the same time you purchase your kit, giving you a percussion and flintlock rifle all in one. Will make a very fine hunting or target rifle. Made in Italy. Shipping weight 12 lbs. Comes with instructions.
Kit 147 .45 cal. Percussion rifle kit .......$104.50
Kit 148 .45 cal. Flintlock rifle kit .........$113.50
$104.50 would cost $347.45 today
$113.50 would cost $377.38 today
That groove to groove size and the Bore size might be a mis-print in the catalog. That would only give it a rifling depth of .002 which is almost no rifling at all when it comes to shooting a cloth patched roundball. A .002 deep rifling groove can be seen but almost not felt if you run the point of a needle across it.
If it is right and you want to shoot this rifle you will need to use a very tight ball/patch thickness combination or, expect to see smoothbore accuracy with your shots.