The front bolts on to cb550 no problem as 500/550/750/gl1000 all use an identical hub. The rear?...I think you would need custom wheel spacers and figure out a way to get a 550 sized sprocket (37t) that fits the 750 hub (commonly available 750 sprockets range from 46-48t)...so custom made rear sprocket would probably be the only way.
Henry Abe's are some of the best looking after market wheels from the '70's imo. They were expensive new, and are expensive now, although values have somewhat descended from the lofty peeks of a few years ago. I have never owned HA's, but they appear to be of similar weight and quality to other cast aluminum wheels of the era, so that means...comparable weight or slightly lighter than stock steel rims and spokes but wayyyy rounder, balanced, and will stay that way unless crashed into large immobile objects or ridden off cliffs.