Well, maint, it appears you are not the new owner of the engraved barrel. Not sure if I would have passed on this because I always default to Fingers' knowledge, along with a bunch of tedious needle file work to get it presentable.
On the same page of the Ebay link you posted, I noticed this:
https://www.ebay.com/itm/Navy-Arms-Dragoon-Barrel-w-Lever-7-5-1851-Navy-36-Caliber-Vintage-Black-Powder/173286176389?_trkparms=aid=222007&algo=SIC.MBE&ao=2&asc=44039&meid=4076597e0be14faaa3a8110df4de3a13&pid=100011&rk=2&rkt=12&sd=183188386550&itm=173286176389&_trksid=p2047675.c100011.m1850
I am a sucker for part round/part octagon 1851 Navy .36 barrels (L&R, R&A, Dance, and my fantasy Pietta 1851 Navy .36 "Dragoon"). This one looks in very good condition from the pics posted by the seller. And, the front brass post sight is missing, which would easily allow for a higher than normal brass rod to be fitted and filed down for whatever POA/POI you desire.
If Navy Arms it might be made early by G&U or Uberti, but fitting it properly is at least half the fun, as long as the bore is serviceable.
I am tempted to bid on it for my future Dance .36 project, but the money in the bank is not there, so it is a pipe dream for me. Sigh.
The guys on Ebay and GB are just working the market by breaking down and parting out complete guns as more money is made by this method as opposed to selling a complete gun. Parts always sell for more than the total worth of the completed item, no matter if it is vehicles, refrigerators, et al. Most people like me are just looking for one part/assembly to modify/repair a gun and those prices are less than new parts if you can find them.
Good luck on your 1851 Navy parts gun. I do not think you will break even, but I have been wrong many times before. The best part of this is that you will have fun knowing you got the gun you want after the purchases and elbow grease.
Regards,
Jim