12 or 20?
I have a 20 gauge BSE, IIRC, same series. Can't tell what the bluing looks like on yours from the pic. Mine has the vent rib. If the lever is well to the right, it either wasn't shot much, or it was rebuilt. Mine didn't take but maybe 3,000 shots before needing a few new springs inside - which needed to be done by a smith as some of the springs are somewhat funky.
I have had mine over 30 years, use it rarely nowadays as i have others. At one point was thinking of selling as most i have seen are running around $600, so $250 is a great price if everything is working properly. Mine is 26" barrels choked IC/M and I used for goose hunting when lead was legal (that's how long I have had it!) using 3" #2s. Thank God I never shot more than a few of those!
Otherwise, I found it a tad heavy for upland when I lived out West, I had/have a few others that were about a pound lighter - makes a big difference when schlepping up and down mountains after chukar!
Have fun with it, it should last a reasonable amount of time with a little care.