Jeff,
I am not 100%, but it appears to be a model 100. These are fine guns. I have a M51 that I use often.
I have found Simpson's to be decent people who try hard to give an accurate description.
Pete
That looks nice. Locks appear to be the same as on my Mod 17. They are machined very clean and after cleanin up have very good trigger pulls. I have been working on the stock and have not had an opportunity to shoot it yet. I need to find some 2 1/2 shells first. When I got it it had a broken hammer screw and the dealer provided a replacement. I took it to the gunsmith and he removed the broken one fine and the new one broke going in. I also broke one of the screws holding the front sling swivel and will have to take it back for screw replacement. I cannot believe how small some of the screws they use are.
If I have to do anything on the one coming the screws will get an application of Kroil and set for a couple of weeks before starting work.