Hi Greg,
You need to build something like this below that I made a while back- a few versions have been devised by people to cut and weld b20 and m47 style bell housings. A fiddle, but not rocket science.
Lord Olga - Do you have any of the conversion parts already? They are quite rare now and becoming costly on the international scene, including for your car an 8 bolt flywheel. I can probably put together most of an m400 kit as used parts, but even then not cheap by the time you have overhauled them for use. There are only a handfull of M410 in Australia, very occasionally they are available for a couple of thousand internationally by the time they get landed - then you have to see what condition they are. I am doing the manual conversion myself this year.