They only drop from the CL 48's RD's in Cooper.
Two weeks ago I looted one and failed the analyze. Took an 8k faction hit before it dropped.
Went back last week and got a 2nd one, lost about 10k before I got that one. Got the print this time, which is good, b/c I ran out of tiles.
Long and short, it is very rare. I can't imagine anyone selling looted versions on the market. On the bright side, I'm sitting at 0 with the Chavez now, although the Psi's despise me.