Darkzero sold a lot of the MiniMag reflectors that he sputtered. The ones I have are for use with Sandwiches. I don't know if he did them for incandescent or not. I think you could sputter your own with practice.
See lambda's post in this thread for instructions.
There's lots of information if your search goes back 2 or 3 years. Darkzero isn't very active lately, he's busy racing motorcycles. He's a great guy, trustworthy and he'll go the extra mile for you. If you want someone to sputter a reflector for you, Darkzero does a great job. Just send him a PM.
If you're going to sputter your own reflectors, I suggest you practice on plastic cups before you sputter a reflector.