Bang on in one, zemjw!
There have been a couple, loose, out of the box (on eBay) at not too dear, and one will remain mostly intact though painted, I hope.
I did try twisting and pulling as hard as I could manage, trying not to break the wheels in half. No joy.
I think I can cut off the narrow lower part under the (steel) axles and then cut down TO the axles. Might be neater with the wheels out of the way, but trying to chop the body was part of the plan.
Wish me luck, thanks for the thoughts, and I really do thank everyone who had a look and a cogitate.
Doug