Not a Spiller and Burr (no matter what the auction description might say), but a Whitney navy, which the S&B is a brass-framed copy of. For one thing, besides the fact that ALL S&B revolvers have brass frames, none has barrel threads showing. This was supposedly done in the originals to keep the inferior grade soft iron barrels from cracking at the breech (the Confederacy did not have access to the best materials, and had to "make do" with what they had. Original S&B revolvers also often show a twist grain to the cylinders because they were made from salvaged wrought iron railroad rails, and were twisted to keep the grain from running in a straight line and presenting a potential weak point).
As for the manufacturer, I would hazard a guess and say Pietta, since they also make the S&B replicas.