Marauder Gen 1 or 2?

What is the difference between Gen 1 or Gen 2? I am looking at buying a Marauder in .25 Cal how can I tell if it is Gen 1 or 2 it does not have the current wood stock with the adjustable stock. How many shots could I expect from a .25 per fill? I did a search on here and saw a lot of references to Gen 1 or 2 but nothing that explained the difference.

Thanks Mike
 
From the factory:
Upgrades from the original version of the gun: Factory-installed depinger changes the sharp ping to a dull thud. Improved valve (increases the number of shots: .177/.22=32 shots, .25=16 shots). Trigger moved back for better hand position. Optional reversible bolt for left- or right-handed shooters. Simplified breech design for assembly, service and to provide a more stable platform for larger scopes.
 
You can go higher, maybe 8 more shots, per fill if you are willing to tune down to the low 700s. From what I see, most are getting 16 good full power shots over 800fps. A regulator should improve shot count if you want to spring for the $. As for a depinger. I made one for my Gen 1 out of clear tubing bought at Lowes for $2? There are plenty of youtube vids on this mod.