235 Barrel All Steel Or Not

I just picked up a Stevens 235 it's all tight and in great shape but it's been reblued so I can't tell if the barrels are steel or if there twist. It has the J. stevens arms and tool co. markings so that means it was before 1915 (there's no markings anywhere on the barrel or rib just some stamps and ser. no. on the bottom flat). Gunsmith buddy looked it over and gave it the thumbs up to shoot but it does have the short chambers and he says that the barrels are fluid steel, but some sources on the web and one book have the barrels listed as laminate so I don't know if the barrels are safe or not (they look like steel to me, no pattern or anything like most twist barrels I've seen)? Anyone know or have a reprint of the 235 in the stevens cat. does it say what the barrels are made of? Also, i'm looking into the gauge inserts for this so I can shoot 410's without all the $$$ and hard to get problems of the 2-1/2 " 12 shells , has anyone tried this?
Thanks in advance for any information it is greatly appreciated.

Never seen one that was twist steel but that doesn't mean much.

2 1/2" shells aren't that costly. You can buy em direct from polywad.com for $10 box, cut down once fired 2 3/4 shells and load em yourself, or even have the chambers lengthened if you want.