Need help with refer model #s

[jfcoll]

Just purchased a 1970 27' Overlander. The fridge is in terrible shape. Latches are bad, inside lining is cracked, broken in spots, just seems to be time for a new one. It does work on AC but I have not be able to get it going with propane. Since most of our time will be on gas with no electric I am ready to replace. BUT, the model # is no where to be found.
The measurements, of the opening, are a 59 1/2 X 24 1/2. I looked over the Dometic replacement chart that I found here and on the Dometic website. Could not find an exact match. (looking under the "recess dimensions" section) There are a few that are close.
Anyone out there with a like setup that can share what their original or replacment model # is?

Thanks...