First of all, are the lenses all glass, and there's an AR coating that works also for 808nm on them ?
7W of laser beam is not exactly a pointer ..... also, if the lenses got overheated, the supports and guides of them can melt or become deformed (i suppose you're speaking about a normal camcorder, and they have usually lens supports made in black plastic .....)
I think that is better get a pair of glass lenses and a glass FAC (cylindrical) lens, coated for antireflective for 808nm, and build a different system for focus it .....
Also, infrared etching/cutting machines don't uses usually galvo systems, for a good reason (random reflections from a shiny or melted surface of a 7W IR beam can blind you before you notice it) ..... do you have protective goggles for IR, and a safety system / enclosure, for your machine ?
Safety first, especially with high power lasers.
Always remember that you only have 2 eyes, and that, til now, spare eyes are not on the market ..... and no, i'm not exagerating, a 7W beam can blind you permanently in like 1/100 of second or less ..... if this happen, you notice that you've lost the use of one of your eyes only when theres nothing more to do .....