Stainless rivets original on Dwyer rig
I've read that the spars and hardware were obtained from multiple sources on the 192. My rig has "Dwyer" markings on most of the items riveted to the mast. All those rivets are stainless steel. I would recommend putting a drop of anti-corrosion stuff anywhere there is contact between a stainless part (including the shank of the rivet) and an aluminum part to prevent galvanic corrosion. Since aluminum is less "noble" than stainless, corrosion will cause the hole in the spar to enlarge and the rivet could eventually pull out.