Thanks replies all. Yes, hardware store rivets seem to be in the 'Pop' rivet category, with a lot of 'overhead' space required. They also don't seem to cooperate well with controllign how tight they end up since you squeeze tool until the head 'pops' off.
Surly, I was just thinking of trying to remember who GAVE me that to give some feedback to. I think you let me have it for postage, so your generosity is again noted :O).
Firstly, let me respond about the rivet question so I'm on topic!
Two rivet problems on the current camera at hand: Welta Perle, Gorlitz Trioplan 2.9/7.5cm lens, nice shape other than the following.
1) In each film spool 'well' are two 'shells' that are riveted top & bottom, not completely tight, so that the shells can rotate on the rivet axes to 'open' for inserting a spool of film. After inserting and loading the film, the shells are rotated maybe 90 degrees (CW and CCW respectively) toward the bellows to 'close'. These shells have the pivot pins for the 120 spools...drive shaft at the winder end. I hope this description makes sense. The rivets should not be jammed tight or the shells can't rotate. It looks like someone removed them on the side where there was a tripod mount. I understand this camera had a 3/8-16 mount, but mine has an unfinished brass 1/4-20? one and suspiciously missing rivets to allow access to the back of the tripod mount... the top of the rivets have to be very close to flush because the camera back closes over them.
The second problem with this camera looks like there was a rivet and screw for the shutter release linkage arm that ran along the folding bed. There are a couple 90 degree turns between the shutter button and the shutter lever on the shutter itself. Looks like the screw was at the 'drive' end and a 'pivot rivet' was in the center of the arm. It's corroded and in a plastic bag with the removed arm (got it that way). Looks like the rivet had two shaft diameters...maybe a larger one that was captive in the bed/door then a smaller diameter for the linkage arm to slide loosely on. Maybe there was a head on the rivet above the linkage so it didn't slip off the rivet.
I hope this description is sufficient, because I know I need a lot of details, being mechanically challenged.
I'll attempt a PM reply on the Argus as it's long-winded (lettered).
By the way, apparently Argus was a Greek mythological critter or being with 100 eyes.