73 Charger non AC heater plenum

I'm restoring the heater plenum for my 73 Charger. I need to remove the Right side fresh air inlet damper. I need to drill out a few rivets.
I searched on line only to find out that there are dozens of different styles of rivets.
Anyone knows exactly what rivets I need? I have regular blind rivets tool but I'm sure that won't work.
Thanks in advance for the help.

Grind the bottom off & measure OD & length add A 1/6 or so to measured length,need to find some with the same style head old school rivet, you will never see the bottom.
for example, Ebay item# 370866624417