What specifically did you need help with? We have parts, and SR/HP rebuild kits for those carburetors. I've never seen one here in the shop, so they must be pretty rare in the US.
Q-jets were also used on the Holden V-8's in Austrailia, we've sold some parts for those in recent years.
I'm also pretty sure a similiar number Q-jet was used on the Ford 429 engines in the early 1970's. I may have one of those in the shop, I'll check the number to see what it is?....Cliff