fan shroud question

First, a wee bit of history. The elderly fellow that previously owned my '73 Dart Swinger apparently had problems getting it to run reasonably cool in summer. He threw money and parts at it without apparent success. One of the first things I noticed upon taking possession of the car was the lack of a fan shroud.

Now I'm poking around the internet in search of a shroud and nothing I'm finding seems right. It's got me wondering if a radiator for something else (E-body, dump truck or something) was crammed in as a partially misguided attempt to help the cooling problem. The unit currently in the car measures something like 22" vertical and 26.5" horizontal. I can take better measurements at specific features if needed.

What should I be looking for to locate a properly fitting shroud for this thing? Perhaps a Diplomat (which would be a step toward an equipment list reminiscent of the Bluesmobile, i.e. cop shocks, cop brakes, etc.)?