You might also try
www.ssfirearms.com for that loading lever. Their parts are usually better than Dixie's. I doubt you will be able to find an original.
Markings could have been removed as part of a refinish job at one time, or the barrel may be a replacement that never had markings. Any guess is about as good as any other.
If you can fit the Dixie parts and age them a bit, it should be OK for your purpose; only you will know the loading lever is not original.
Jim