Alvin,
Thanks for your input, appreciated.
As you probably guessed, I am in Australia, Brisbane, Queensland in fact.

I have removed the 4 little screws you mentioned, but can't yet separate the frame.

I had pretty well figured that there would be a joining piece at that point of the frame.

What has me intrigued is does the front piece of the frame separate from the back section , OR, is it just 2 pieces Upper & Lower?

I do have it soaking currently, will leave for a couple of days.
Rust is pretty bad, and I am resigned to buying a new frame (if available) or trying to fabricate something.

I need to try and get some dimensions of similar frames in the US sedans & later Chev Pick ups & trucks, so anyone that can help with that would be appreciated.

Thanks,
Bill.