Latch repair on Cobra trailer

I've managed to do minor damage to my new Cobra trailer already

One of the clamshell latches snagged on something during ground
maneuvering and pulled hard enough to pop the bottom rivet. Upon
closer inspection, I found the factory used a bolt for the top, which
held firm, but I cannot replace the broken rivet with a bolt because
there is no way to get a nut on it, and there is not room on the
inside of the trailer for machine screw head or nut because of the
tailgate clearance (less than 2mm).

The rivet itself left a hole too big for the 3/16" rivets I tried to
use. It looks like it would take a 1/4" rivet but I cannot find those
anywhere.

Any ideas on how I might re-fasten the bottom of that latch plate?

2NO