Mine is #21361 and the barrels are damascus. I was guessing 1883-4 based on serial and Henry PUN. Have you looked at Argo's thread on Reillys over on doublegun?

http://forums.nitroexpress.com/showflat....true#Post362421

To your question about damascus barrels possibly being blued to appear as steel, the first known Reilly with steel barrels is #19953. This is from Argo44 (Gene) writing a history without benefit of any remaining company ledgers.

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=436538&page=97

Can't wait to see more pics when you receive it.

Chris