I've done the same thing and gotten the Corbin Young Guns seat for my 06 SEUC. The Corbin hardware I have connects only to the fender posts where the stock back rest bracket attaches. Its a simple matter of removing the nuts from those screws to lift off the Corbin bracket and replace it with the HD stock back rest bracket. Takes 5 minutes because I'm slow.
My seat was ordered as a CVO version but unbeknownst to me when it arrived, it came as a standard version though it had the ostrich center panel and stitching like a CVO version. I believe the difference is that with the CVO version, there may be a second Corbin connecting post in the front of the seat that you may have to attach to the frame, where with my standard version, there is no front connecting post and the seat pan has a tongue that slips into the frame hole just like the stock seat, with only the rear connecting post. The problem I have with this arrangement is that I cannot use the seat with my detachable tourpak as you have to place the front tongue into the frame, then push the back part of the seat down on the rear connecting post. You can't do that with the tourpak on and if you put the seat on first, then try and attach the tourpak, the rear cushioning in the seat is too high to allow the tourpak to mount on the posts. I should have sent it back but didn't discover the screwup until almost a year later when I decided to try and mount the tourpak with the Young Gun seat. I use my stock seat whenever I use the tourpak.
If you don't ever plan to use your tourpak with the Young Gun seat, I'll be happy to sell you mine and I'll order the CVO version. Good luck with it. You'll enjoy the look without the tourpak.