I've seen the actual nose piece tool, which I'd like paired with same brand rivet gun. "More toys"
I've found a few searching google but each lacks spec on diameter, which I'd like under 12.5mm. Be nice if someone with tool could steer me in right direction.
BTW: I'm thinking corrugated cardboard between glass & gun would good protect form shock.
I see your question was old now, but I had the same question and finally found it. I vowed to post it here also if I found it. It's in this post: Windshield gasket parts and such - https://forum.ih8mud.com/threads/windshield-gasket-parts-and-such.1286653/ I called the 1-800 # and got one. It was $27.35 + shipping. I got it more out of spite to prove to the idiots at the windshield place that it actually exists. I'd for sure try taping some nuts together that fit in the gap and building a spacer if I was doing it myself.
Resurrecting this thread to share my experience. I had to pull the moulding from one side to address water ingress near the top corner of the windshield which caused drips from the overhead console.
I used the cheapo $5 Harbor Freight rivet gun with a half-inch aluminum threaded spacer from my local Ace Hardware. This was sufficient to clear the moulding, but leave enough of the rivet tail that the tool could grab. The rivets were overall not as daunting as I had expected.
I used a small diameter socket with a similar diameter as my rivet gun for the extension. Rivet passes through the socket to the gun, works as normal. Don’t overthink things - no need for special tools on this one!