Non A/C box. I had it posted on BigBlockDart site 10 years ago. They had a heater motor modification on there. I lost all my documents (Pics) on photo bucket. I did have to change the squirrel cage with one from Grainger. May not have been necessary though. I believe motor was from early 90's...
Maybe one of these?
68 69 70 71 72 CUDA CHALLENGER CHARGER GTX DART OEM C12 SEAT BELT BOLT C 12 | eBay
1968 1969 1970 68 69 70 Dodge Charger Cuda GTX Mopar B E Body Seat Belt Bolts | eBay
Seat Belt Bolts For 1968-70 B-Body Dodge Plymouth Charger GTX Roadrunner Coronet | eBay
Might be able to weld in a repair panel but I agree buy the full replacement.
https://www.classicindustries.com/shop/1963-1976/dodge/dart/parts/suspension/front-suspension/torsion-bar/
I had a 70 Duster my friend built. He had an MSD box but kept the stock ECU and wiring. If the MSD failed it took little to hook the stock box up and get home. I never had to use it. Wish my Hardtop Dart was wired like this as I did get stuck from an MSD box. Now running stock. I may go HEI and...