Yeah!
This oddity was indeed a between-wars innovation... one which apparently did not long survive (in production, anyway) its contact with the real thing
Folks often seem to say things like "necessity is the mother of invention"... here, I think we're really talking more about "idle hands make for (expensive and needlessly-complex) mischief"!
It IS on my to-get list. ALWAYS has been, ever since I first saw a pic of this thing in some old book oh, about 50 years ago.
FYI: a built example of this kit has recently been posted for sale on eBay. Looked pretty OK - actually really neat as a kit. Seeing the build did raise a question for me... maybe someone out there will have some answer:
Take a look at the wheel positions on the build (on eBay, or...). Looks to me like the wheels are hung pretty close to the tracks... was there any ability to steer this thing on its wheels or did it pretty much need to roll along in a more-or-less straight line? I don't see how it could turn much inside the turn-radius of the Titanic, given as there seems little clearance for turning wheels...! Perhaps this thing had 4-wheel steering, like the SdKfz 222?
Bob