I said "eff it" today, and after a quick trip to Lowe's to pick up some steel I did a front pin conversion on the race car. It was an easy fab, took a couple hours, including a beer or two while I mulled out exactly what I was going to do.
1-1/2" square perforated steel, bolted to the stock firewall bracket (so it can always go back easily). 1/2" hood pins through the holes. Removed the hinges from the decklid (used a drift to punch out the pins in 3-4 good whacks) and the front edge of the decklid rides right on the square steel at the right height. Couple holes in the decklid, adjustment of the pins, done.
While I was doing this, I thought of a way you could do your removable decklid in semi-kit form. First, the end user can punch out the existing decklid pins easily, it really didn't take a lot for those splayed-out ends to give up. After that the only mod that has to be done to the decklid is to slot out the front of it to allow it to slide in, and you can provide a template for buyers to use to know where to cut. So in the end the buyer just needs a drift to get the slot out and some metal cutting tools for the slotting.
You'll get a stack of the hinge brackets and mod them as needed (I can provide to you the first pair from the race car). You'll provide these modified brackets on a core/return basis so that you never run out. Along with that, you'll provide modified shank bolts that you've modified with the flat, and the user will install that with washers and Nylock lock nuts into the location where the hinge rod used to be (with instructions on the required orientation of the flats). Or maybe you fab up a specific threaded rod that could be inserted in its place?
So, users buys hinge brackets and flattened rods from you (with a core charge for return of their hinge brackets). User drifts out the stock rods and removes the stock hinges. User grabs your template, places it correctly on the decklid and mods to your instructions. User bolts the two provided hinge brackets to the firewall and slides in their newly-removable engine decklid cover.
Done.
GA