Could be wrong, but I am thinking the extra bbls are E 11885. I can readily see bob's point on the 5. Also look closely at the F. Right in the line of one of the damascus swirls it appears to be the up-turned point of the lower arm of an E, which exactly matches the down turned point of the upper arm. I think the E just didn't fully stamp. I suspect it was returned to the factory for a 2nd set of bbls & for whatever reason was fit with a set of E bbls. If you notice the damascus figure it is coarser on this set than the 30" originals, in keeping with E grade bbls. I suspect factory done because of having both SN's, though some enterprizing gunsmith could have done so.
