I voted weapon because wearing them on a kevlar really really sucks. I had the sevens I think they were. with 2 ocular lenses to one objective. Very heavy. The 14 is obviously lighter but youre still trying to line something hanging off the front of your head with optics or sights. If you don't have to wear them don't. Do you have an ir light or laser? What are you doing with the application? I mean just shooting is one thing but if your moving/walking or anything you may want a head or helmet mounted device.
Yeah id do it with weapon. Not sure if they have a flip to side mount for it but the weight on your weapon is alot better than wearing it on your head. Having to is one thing but wanting to is like who really wants that. Either way cool that you found a deal. Are they the real deal or kind of like a civilian version? I imagine you're familiar with nods anyway. Have fun.
depends on what your doing imo, if i am navigating through a dark woods looking for some unlucky animal to pop out then helmet, but if your posted up somewhere then weapon mounted, i run an envis gen 3 monocular
keep in mind from what ive read, a t-1 has issues when running a 3x magnifier on the pvs 14
I'd invest in both mounts; rifle and a head/helmet mount (whichever you'd prefer). Just like bigdog said, moving around you'll want it on your eye pretty much constant for navigation. You can do that with it on the rifle but it'll get tiring real quick, not to mention that you'll be pointing a rifle at everything you see. If you're stationary though rifle mounted is the way to go, especially with a bipod mount.
The 14's aren't as bulky wearing on your ACH as the 7's. But then I never minded either much, I guess you get used to it after awhile though I'm waiting for someone to come out with a study showing long term NV viewing is bad for you!