The hood rests have a thick rubber cushion held in place by a special LTD nipple with a 5/8" long 3/16" BSF thread, which screws directly into a 1/8" thick shaped retaining plate. (photo shows the plate with a similar nipple, but with the threaded portion being too short).
When the hood is folded, the leather strap is simply wrapped over the folded frame and fastened by means of the LTD fastener furthest from the rivet, directly to the nipple on the hood rest, thus leaving the nipple on the hood frame unused.
I have never seen an original hood bag. It would seem likely that it would be at least partially secured by means of a LTD fastener pressed onto the now spare nipple attached to the hood frame. I would be surprised if any straps provided for this job were separate and detached from the bag itself. I would imagine that they would be sewn in - even cheap tool wraps were made this way.