The slide is stanless but the frame is aluminum alloy. It looks to be a NIB Mark III, it has been well taken care of if it has been shot.
The Shorty 40s where made in different series, the first generation Shorty 40 appeared around 1992, there were some 1500 pieces made of the 1st generation. In '94 the 2nd generation appeared with only minor modifications to the pistol, only the checkering on the front grip strap and a longer beavertail are visable. The highest serial number I have heard about on the 2nd generation is just over 200
The 3rd generation appeared around late 94/early 95 in blued and stainless with adjustable sites and drastic changes in machining to the slide. You may notice that the machining on the slide on the MkIII is very similar to the slide of the current M&P line. I'm not sure of production numbers for the 3rd gen guns, but I can't see more tha 1500 or so like the original production.
The last series of these pistols was the Shorty 40 2000. This one is more of a two tone pistol, it's a very nice looking pistol to me. Again I'm not sure of production numbers but I'm sure it wasn't a lot.
I've got two of thes, a 1st and 2nd gen, they are my favorite pistols. They are very accurate and definately my go to pistols. Price on this one if it is in fact NIB I would put around $750.00 to $800.00. Grinder said not long ago he sold some nice ones for $700.00, I trust his judgement on price since he's the resident PC guru.
Here is what the 1st and 2nd generation look like:
Shorty 40 1st Gen
Shorty 40 2nd Gen
Cheers,
Sam