Door panels.

I need some help from you GM guys out there.
I've got a '73 El Camino that I just started on.
Most of it is in decent shape and it should clean up in a few months.
The interior, on the other hand, is ratty. I've already pulled the seat and carpet, and the dash may be next.

I'd like to replace the door panels, but don't want to use the two peice one's unless I have to. do any of you guys and girls know if any of the ElCo's in the same Generation ('73-'77) used a one peice door panel that will fit onto the '73 door frame?

If not, how about a source for new two peice panels?

Thanks a lot y'all.