Fender is a Harley Fat Bob rear. I think some fatboys and wide glides use a similar one. I got this one at a local place called the Jebby Shack for
$20, all their used fenders are the same price. Check your local independent motorcycle shop that specializes in Harleys. They are bound to have a room full of cheap used parts. Ask if you can poke around, maybe take the part outside to see if it fits over your tire and between the shocks. This one had the all the bolt holes filled and bar stock welded on the inside sides to eliminate the stock side rails and a plate welded in the back for an aftermarket taillight and license plate. It was very professionally done, which is why I butchered it cutting those out.
You can literally make any fender fit very easily. Works best if you remove the tire, but you can jack it up and drop the shocks for a little more room too. Cut the fender to the relative shape you want and notch it to clear the belt, mock it up to where you want it, mark the bolt holes, drill holes, mount it, and ride it (I don't care about painting this one because its mangled, kinda matches the ratbob look though). Top frame rails are kinda far apart, so this time I put a bar between them and drilled mount holes in that. I'll get pics later. I have used the same process on 3 different fenders I made for this bike: a trailer fender, xs650, and this one.
PS. Chris, I like your avitar