Got semi-lucky I guess. I took a good look at the brace this morning and one of the clips is still on the brace. It appears to not have rubber on it but I'm not pulling it down to figure out for certain. Now I just need to find another one as I dug through most of my stash buckets for over and hour looking for the clips and firewall pad pins. I found one pin, need to find another. I had a few that were rotted away from the old firewall/cowl water damage. I've been trying to scavenge them when I come across cars and save them, just have not found enough of them yet
A buddy has a dead 66 coupe we hauled home years ago so I'll check it for the clips and any firewall pins I can swipe. My biggest trouble I'm having with this repop firewall is the sheetmetal screws pull through the metal pretty easy when torquing them down. One of the other problems is a couple extra holes that they must have used for 65 to 70(what this firewall was billed to fit). The heater hose holes are also huge, which it is too late to weld them up now. I bought a set of 69/70 heater hose grommets from NPD that solved the problem. They don't look correct for the concours finish but the thought of gooping the openings with sealer to fill in the huge gaps did not sound exciting. MCA judges and other purists will frown on them but they might also frown on the late model power brake booster on the other side. I may try spraying them with the sealer and crusting them a bit to "hide" them some.
My goal is to make it as correct as possible, in hopes that when I open the hood the average person will feel they are looking at a "new" and correct 64.5 Mustang. I'll take a few pics in a little bit and post what I've got.