This is great, and I agree that a 1.6 adapter would be useful if possible. I am building an Xbox test bench and right now (mainly involving dremeling stuff off of an Xbox case, also building a sturdy area for swapping HDDs), but need to swap out PSUs for different Xbox versions. Also I need to build a cover for the PSU area so that I don't stick my hand in there. An adapter for 1.6 Xboxes would allow for single, safely enclosed PSU with an Xbox test bench, just a thought.
Xbox Linux and Linux-wrapped apps will only work at 640x480 on a 1.6 Xbox, due to the Xcalibur chip, whose API hasnt been published by Microsoft. Also you can't upgrade the RAM on the 1.6, since they removed the solder pads from the motherboard.
I'm also interested in this; it would be great to get a complete version of all the maps together!
I'd also be glad to help if needed with the map pack