I have an SKB 280 12 ga with 28" barrels-M/F for chokes. I think that the majority of the 26" barrel models in both 20 and 12 ga, were choked IC/Mod, with the 28" barrels being M/F.

There were probably runs or perhaps a few of the 26" barreled guns made in M/F. Someone with more knowledge than I will probably chime in at some point, although you didn't say whether it is a 12 or 20 ga. Not sure that matters though.

Cameron Hughes