Looks like a beauty that's for sure! A 10XL perhaps? My friend has one like it and I think his is a Special or a Super, kind of rare. I'll get back to you on that.
Not sure why your pictures are sideways but I'll see if I can fix them for you. Next time, before you upload try to crop the pictures, even just take a sliver off them. That's helped me overcome the problem on email and other forums in the past.
Super is a Suburban with the bigger engine I believe. Those are very cool. The other one like this custom is a compact. It's the lower end without the hi-lo like this Custom looks to have I believe. Customs looked to be the best of the Suburban (633a Hi-Lo) while still being smaller like the compact.
I'm pretty sure this one is like the one @RCG used in his build-off entry last year.
I agree, Customs are pretty cool!
@redzz02 shared on Facebook the custom I love the looks of. He saved his from the scrap yard.