1939 Ford Convertible frame

[blucar]

Many of the joint fasteners on convertible tops are riveted. I would be very slow to remove the rivets because it is very difficult to replace the rivets.
A good penetrating oil like BLASTER will loosen the joints, a second option is to use a combination of heat from an electric heat gun with a good penetrating oil.
I have been involved with the restoration of three pre 40 convertibles all of which were Briggs bodies. Many of the top fasteners have chrome plated heads which are unobtainable. I had to have new bolts made for the connections with bolts. Many of the bolts are shoulder bolts that have to go through two layers of steel, therefore the shoulders have to be smooth, no threads on the shoulders.
I had bolts made out of stainless steel, which I polished, thereby simulating chrome on the exposed side. I had nuts made that simulated a rivet head with a countersunk hex hole for tightening on the concealed side.