My MM conversion took over 12 months on and off using the shell and boards of a project NBAFB.
It was a massive undertaking and was started well before the MM Clayton versions were announced.
At that stage I was about 65% complete so I had little choice but to finish it off even though the motivation was waning.
The task was made somewhat easier due to the fact I have an original machine to compare it to, but the real assistance were the CAD and AI files that WallyBGood from the US sent me of the various habitrails and componentry containing detailed measurements as I wasn't all that keen on tearing down the original and having two lots of parts laying around for what would be essentially the same machine.
I agree with robm, I have no problem with a machine being converted as long as there is disclosure as to its provenance to any potential buyer down the track.
For serial numbers, I just copied the ones from my original and added a +1 to the end.
I still have both MM machines so it can be shown exactly what the origins of either machine are.
