1. According to Ars Bella Gerendi (About the 30-Year war in XVII Century Europe - the book contains scans from an original XVII Century German "Manual") a puffer was used as a club after the shot has been fired - therefore the ball was useful
2. Ornamented Puffers were only for the elite noble around 1580-1610, the Soldier used a weapon like the one in the first picture.
It is much more comfortable to hold as it it designed to be a one-hand weapon.
It could be used in 2 ways:
1. Cavalry Line with gun outstretched, marching towards the enemy (marching, not galloping) as if they were holding a longsword (long, pointed, evolution of the lance, no sharp edges, only used for thrusting). In this way they were used by the "Cuirassier's"
2. As a sort of left-handed melee weapon (usually done in Poland in the XVII Century):
A soldier fights with a sabre, mounted or on foot. He would fight with the sabre and use the loaded gun as an additional weapon when surrounden by more than 2 enemies.
After the shot is fired, he turns it around and uses the butt as a club - the officers usually had small clubs with them, they were ornamented and used as rank insignia but during a battle were also drawn for a fight. The soldier just used his handgun.
If you wanna go for the second stock, i'd rather say it's a later gun with a wheellock fitted, not a period army-wheellock.
Here are some pictures of a replica Polish Wheellock Carbine:
http://allegro.pl/item857270642_strzelba_mysliwska_cieszynka_xvi_w.html
They were manufactured from around 1590 (that's when the factory was officially established in the town of Cieszyn=Polish/Czech Republic Border town - back then it was 100% a Polish town.)
I'd buy that part if it werent a non-functional wall-hanger (well, it's functional but the barrel isnt made for shooting and no vent drilled - also the wheel turns but doesnt spark) - the auction start price for this deco-part is 2000$
I'd really love to have one but fully functional - anyone eager to build it ?
Even without the ornaments