These original 1948 heads had been "upgraded" to o-ring style. It wasn't a nice "upgrade" (if you get my drift?) Kinda cobbled. It took a little doin' .. . but we got the stock style plumber back in there, and used some sealer. Then we drilled holes, and manufactured our own mild steel rivets with factory style heads (after viewing photos). The rivets were press fitted, with sealer, and peened on the inside like stock. I painted the rivets with cast-iron-gray high heat.