The source for the lgp506 (Aka LG Thrive), im hoping devs well get on this, and apply a p506 version for there existing roms, for them to work with the p506 correctly. Otherwise, from what i've been able to surmise is, the only issue with porting roms from the p500 to other variations seem to correlate from the kernel.
and in regard to the p506, the current cm7 rom port works, only the screen is 8-bit and showing only 3-4 pallets of blue.
Hope this source helps out.
if you dont like or cant use multiupload, other means to get the source is just going to http://www.lg.com/global/support/ope...opensource.jsp and searching lgp506go.