I'm lucky enough to still have a paper copy of the '91 red and blue catalogue so I was able to trace the dimensions and cut a frame to match with Plasticard girders. a lot of poking around got me to this stage.
That worked but didn't look quite right. there didn't seem to be enough space to fit enemy troops under the mallets and blades.
Out came the Greenstuff and I straightened out the centaurs arms added a Pavaise Shield and I did some fiddling with the cams. which leads me to where I am now with this
I've mounted it on its base so the wheels can still be turned and the mechanism works. I'll make a video of it working if I can work out how to make my camera take video and then post it here.