Paul not exactly tried many alternatives except I did try a cheap screw on wide angle converter and that would not focus. Just happened to have this old pentax K mount TC hanging around and tried it - rather suprised it seemed to give a pretty good image.
DQE -think you would have to make an adapter from say a 58 mm filter holder thing superglued to a lens endcap which has had the centre removed. Not sure if you could make a sensible removable adapter for the MT-24 on the other end though. Suspect though I would probably be trying to shoot larger subjects in natural light.
I actually used to use these camping mat tubes routinely for reversing 50mm lenses onto my 105mm macro without any problems.
Brian v.
