Some pics of the lens and reflector I just received 
Lens is left covered until assembly to avoid scratches and dirt.
The lens is custom cut (by the manufacturer) from 3mm thick AR coated float glass window from Edmund Optics.
Reflectivity is almost 0%, and transmission is close to 98%.
The reflector is a 220mm diameter parabolic aluminum-coated reflector, also made of glass and from Edmund Optics.
Hopefully the additional rigidity and precision of the glass compared to my last build’s electroformed reflectors provides an even more focused and sharp hotspot.
It should be a tighter beam regardless, due to the longer FL and smaller light source I am using in this build.
The goal is a sharp pencil beam with low divergence!
The edge of the reflector has a flat all the way around so instead of gluing a mount to the back I am going to change the design a bit so that I clamp down around the reflector to hold it in place.
Currently finalizing the CAD design so I can order the metal parts for the body of the light in the next few weeks.
Cheers everyone!