Sorry, I can't really help there. Mine didn't give me enough trouble to remember them. Most of the frames were chromed brass, though, so that's probably what you have. I've only ever seen one of the aluminum ones. One way to tell is to look at the Tenax pegs for the soft top; on the aluminum frames there is a slotted screw head visible on the side opposite the peg.
One tool I've found useful in similar situations is a "hand impact tool"
https://www.northerntool.com/shop/tools/product_36882_36882
Mine takes 5/16" hex bits, so it's fairly easy to fashion a custom bit from a 5/16" Allen wrench. Here's the one I made for some tiny plugs on an old tractor carb last year:
Try to get the tip to be a snug fit in the slot, as that lessens the chance of stripping it.
I forgot to take photos of the little ones, but here's a shot where you can see one of the bigger ones. Some of the little ones were down holes (which is why the tool is so long). I couldn't budge any of them with an ordinary screwdriver, but all but one came out with no damage using the impact tool and custom bit.