I really love SGs. I've only owned one (also has 2 P90's), but I've played many over the years and always read about them and study ebay listings. I guess I'm an avid SG enthusiast...
I've owned a couple of strats over the years. In general, I'm not as huge fan, and am not familiar with the deluxe, but...
I'm not sure I'd make that trade. Check it our by all means, but I think your strat model is pretty nice relative to other strats, while the '72 pro SG is not a great model compared with SGs as a whole.
Aesthetically, I just think they look kinda cheap...it's gonna have those two small pickgaurds, dot inlays, probably no neck binding, a huge bigsby and the body isn't sculpted like the classic SGs most are familiar with. The horns are just cut at a 90 degree angle which looks wrong to me anyway.
I don't know. If it plays and sounds nice, it's probably worth it, by in my opinion, the only thing that SG probably has over your strat is its age.