It looks like a good one. It is indeed a dual stage with a cga320 input and the secondary gauge is a good scale. It probably is manufactured by Victor, can't say for sure.
More importantly, the seller will take a return in 7 days. For that price it is worth a try. If worst case scenario, you had to have it rebuilt, you still would be within a reasonable purchase price. I had a Victor blow a diaphragm once and had it rebuilt. I still was happy with it. With the low output pressures we use, it is not likely happen to often, even if the regulator is old.
Looking at the picture again, the gauges look brand new so, it's possible the regulator has been rebuilt already.