Hey Chris, I like that model too. I have done a few of these over the last couple of years since I started. I have come to believe that the 720 was like the "flagship model". I also got the impression that they came out with the 4hp briggs not the 3.5hp that is on yours. I have seen all the 520's with that engine. I may be wrong but most of the ones I have touched have had the big engine. But Mate! if we could categorize them as the military article I think they may be in the Armored Division. Sold as a rock. Maybe harder. regards.
