Looks like either a Loboy or Street Sweeper fender. Try the usual places online like J&P or Jireh Cycles for price and wide selection. Just using a google search I came up with
this link. Now an 8.25" fender MIGHT fit, but make sure you measure. Can't remember if our bikes take an 8 or 8.25 inch fender. Been a long time since I've had the rear fender off and measured between the mount bolt holes. You should be able to find something that's at least close to the bike in that picture for $150-300. Still would need nuts welded on the inside of the fender, and of course painted. If it was my project, I'd probably look into either different fender struts(something not as wide or thick as ours) or eliminating them altogether.
Good luck, and let us know what you come up with.
