Oh man.....did you get to see them live?? I've only seen them on Austin City Limits what a show!!! My Dad used to play "She's About A Mover" by Doug's other band The Sir Douglas Quintet at parties when I was a kid. I've been into Doug's music since then. Definetely a bummer when he died. Is your brother-in law still in the music biz? 
Nope he still has connections as I was trying to see if he could get something going for Lior.  It was a long shot and I have better leads elsewhere. He did say Doug was a talker. Could not shut the guy up. I never saw them and the only recording I've ever heard

http://www.amazon.com/gp/product/B00000JJNP/sr=8-5/qid=1144289640/ref=pd_bbs_5/002-7858125-5904839?%5Fencoding=UTF8

I did meet Augie Meyers when he was hot with Hey Baby Que Paso but really hate Salza music. I think whoever gave the Mexicans an accordian should be shot :)