I checked War Baby and they show that Inland sent 10 barrels to Rockola, probably to assist in the design of Rock Olas barrels. It also says that Inland made 35K barrels for the free issue program but most went to SG production.
Your carbine probably had the barrel replaced at some point in its life and you now have an almost new barrel on your carbine. That is a plus. I would not worry about it affecting value much as Rock-Olas are so scarce and so desired that ANY Rock-ola will have great value down the road.
Rock-Ola barrels have a problematic past as a lot of them were rejected for use for various reasons many by being bent. The SA armory finally sent around their guys to look things over and they straightened out the bent barrels and cleared them for use. Bent barrels were very common in the manufacturing process and these SA people would just use an arbor press and their eyeballs to find and straighten the bad barrels, rejecting the use of machines to identify the problems.