One of the first jobs I tackled was modifying the engine flex plate.  The standard plate that sits between the 20v and its front wheel drive gearbox has the starter mounted on the opposite side to the T50 gearbox that I have.  Luckily all that is required to match up the plate to the gearbox is to cut a hole in the opposite side of the plate and patch up the existing. The plate already has the correct shape for the cut out which is handy.

In this photo you can see the new cutout.  I used the left over cut out material to patch the hole on the other side. I welded it in place and then smoothed the welds out with the angle grinder. Lastly I trimmed the excess off to with the jigsaw to complete the round shape.

A surprisingly straight forward job and looks like a bought once a quick coat of paint was applied.