I would appreciate it very much if you would post your impression of the light output improvement results and any further modifications needed or obstacles encountered.
I maybe interested in modifying mine. This is the third season for my Vega and I have not used it enough to tell for certain, but it appears that my runtime has dimished also. This light has good optics and a nice case so I thought it would be an excellent candidate for upgrading. My battery life had not deteriorated to the point that I was willing to open it up yet and economically it makes no economic sense to spend the dollars for a factory refurbish.
For now I have a Princeton Swithcback 3 that I purchased on closeout at Colorado Cyclist and paid about the same price as my Vega. It is working fine but the switch was defective on the first unit so you never know when it could quit working and I might need a backup. I have the PT SW3 on the bars and a Fenix on the helmet and like the combination. If I had not about the Fenix sooner, I might have one on the bar as well instead of the PT SW3.