Yes, yours is a little more rare because it is Persons made. The manufacturers back then typically sourced the seat and the sissy bar from the same manufacturer. So CRASH is right, back in 1968 the bikes would have a 48 inch sissy bar, but if the seat was a Persons, the bar is made by Persons, Troxel seat, Troxel bar.
There are differences in the way they mount, Persons mount from the front with those clamps you have, but they basically look the same. For Huffy Rail and Wheel bikes, the seats were typically Persons made, the ones with the glitter color and silver mylar stripes. The 48 inch Persons sissy bars for them always seem to be missing from the bikes. The member Railrider on this forum paid $200 or so for one on eBay a while back, that's how rare they are to find in nice shape when you need one.
The seat on that bike is rare too! A Persons made striped seat. You have a neat bike there!