[Killer Bee]

a common frame attachment fastener that looks like threaded rivets are called Huck bolts..

https://www.afshuck.net/us/en/Produc...HuckBolts.html

Unlike any other fastener in the world, HuckBolts® are precision engineered two-piece fasteners that, once installed, never come loose. No matter how vibration-intensive the environment, HuckBolts stay put. HuckBolts provide direct metal-to-metal contact when installed, which eliminates the transverse vibration often found in conventional nuts and bolts. Engineered for a wide range of applications, HuckBolts deliver superior joining strength, shear, and tensile strength for an unmatched fastening solution.

good luck!