It's for sure NOT based on Ford's Model A chassis. An 'A' ('28-'31)has a 103.5 wheel base, minimal rear kick up and none in the front - it's virtually a flat chassis. Of course, for a rat rod it could use anything.
This is TCI's version of an 'A' frame and while it has an IFS and a 4" rear kick up for coil overs, it is the same general shape as an OEM (and I have had an original '31 sedan body on it).
My opinion, if you can sell it, you might be best off. A workable 'A' chassis can be easily built with a welder and some 2x4 x .125 to .180 wall tubing and a pair of frame horn repair sections