I'm not htere to see it, How much Play are we talking about? If it's slight, under 1/8" or so, your Probably OK! I'm not trying to be insulting, do you know how to field strip this weapon? If you remove the Rear cover, the Recoil srping assemply and Remove the Bolt, with Piston, you should be able to tell if the tube is too loose and see if maybe you can slide it to the rear and get it tighter? Remeber AK designs, Like the WASR-10 are Prety tough, your not likely to break anything try to fix it, go to it and let us know, how it goes, we will try to help ya ll we can, OK?
PS: Could be why they let it go, but that's not meaning your in trouble with this, OK
My WASR10, and Polish underfolder both have play in various areas including the gas tube. It isnt cause for concern as long as your rifle functions properly. With AKs loose parts just seem to be the nature of the beast.
This tutorial, http://www.gunsnet.net/Linx310/gascantfix.htm, will tell you how to tighten the gas block if you choose to do so. Although the tutorial is on how to straighten a canted gas block, you can infer how to tighten one as well.
A gas block that wobbles is not normal. They are usually very firmly mounted on the barrel.
on mine it wobbles a little bit, but only a very slight amount - it operates fine.
i don't know a crapton about guns, but i suppose there is one of two problems if it wobbles seriously bad:
1. the gastube takedown lever isn't locking the tube in all the way- (i dont know if you know how to field strip it) but if that's the case, the lever is on the top right of the gun, right at the front end of the rear sight. the lever should be pointing toward the trigger (in the 7-8 o'clock position looking at it from the side).
2. the wedge that locks the gastube in place might be worn down somehow, in which case idk how you'd want to go about fixing it. you might be able to tell if it's worn just by looking at it, it's connected to the hinge end of the gastube takedown lever at the rear end of the upper handguard. - to get a real good look you'll have to take the action/piston out and such and remove the gas tube.