First post. Need help with Crank register diameters!

Hi everyone!

I currently have a 64 Dart in the shop with a 225 /6. The guy brought it in because the flex plate was broken. Apparently there are a couple of different size registers for the crank where the flex plate mounts, and I'm trying to find a place to source a flex plate with a register diameter of 1.960". the one that is listed from my parts places are 2.150" ID. the torque converter has a 10" bolt circle (apparently it's not the factory transmission).

Any help would be greatly appreciated!
Thanks