seems lemlux is planning on doing a bulb purchase at WA - the original manufacturer of the 6AA and 8AA bulbs - the 6AA is the WA 01286 bulb - 4.2V 700ma.
4aaa to 6v - check my website - click on the graphic, below. Go to the MODS section and look for "Dbl. Barrel 6 Volt Mod". The conversion was submitted and posted on my site for everyone's reference