First off you might want to look into a photo editing software to scale down your pics so they'll fit on one screen frame.

The rear frame horn covers attach to the fenders and the rear body lower edge, since it looks like you're building a hiboy they wouldn't look right hangin' out back there. Hopefully you got the tank with the rounded shape on the ends like the stock tank, and not the one with the squared off ends which wouldn't look as good.

Take a look at these; http://www.stevesautorestorations.com/catalog.php search for "rear body lower corners" (stupidly designed web site won't transfer a direct link)
it's a nice way to give the rear of a hiboy a more finished look from both the rear and the side. You might check with your body manufacturer to see if they've done something like these in glass. Or check with Barry Lobeck, http://cleveland.citysearch.com/prof...rod_parts.html He's the guy that originated these.