Of the 7 lanterns i converted 6 to warm white, for the seventh I’m still fighting with the heatsink.
5 of them are this 4xAA lantern:
It’s a kind of clone of the UltraFire ZF6248: http://www.fasttech.com/product/1230501
A little demo: https://www.youtube.com/watch?v=PszlrClLuwE
Surprisingly, it’s “better” and cheaper than the original: grey, no blinky mode (despite what the packaging says), and around $17,50 (converted from EUR) before sales tax (well, the Euro is getting destroyed).
I’ll post a beginner-level how-to guide for the emitter swap the next days, I made a few photos while “mass-converting” three of them yesterday.
The other two are 3xD big ones, and harder to modify:
I have several others, but failed to mod them to something useful, so they are now scrap parts and I don’t count them.
About 10:1. I do have about 5 lanterns I'm cannibalizing to build a lighgthouse though. Just wish I could figure out how to use the leds from them as they are but I am currently only using the fresnel lenses.