64 dart convertible bench seat cover

This is my first thread. I have a 64 dart convertible with slant 6, automatic(push buttons) trans.
I purchased this 25 years ago and kept in the garage all the time. I'm currently restoring the car and most body works were completed. The engine and the trans were rebuilt and ready to put back into the car.
I'm looking for a new seat covers. Mine has a front bench seat and it seems like nobody has a front bench seat cover for 64 dart convertible.
This summer, at a local Mopar car show, I saw a restored 64 dart convertible with a new front bench seat. Unfortunately I could not find the owner to ask about his new seat cover.
Can anybody help me where to get new bench set covers for front and rear?

I'd appreciate for your help.

Aki Tsuji