I modified the laser nozzle today using the lathe. (first actual repair/improvement of something with the lathe).
I cut a small groove so that when you tighten the thumbscrew it pulls the nozzle into the housing. While taking the measurements I had to disassemble the laser head, so I'm sure the focus is off. We still need to order new lens as the one that's in there has a few scratches and I think a small crack. I seem to remember finding them on Amazon or eBay for around $20. I think it's a 23 mm diameter lens, I'm not sure what the focal length is.
I put it all back together but of course you're going to want to check the set up.