Mainly so the rest of us know who we can ask questions to, i know "a few have done it" but no idea exactly who has.
i'm part way in to mine & need to ask a couple o questions to get parts ready to order.

eg.. what CBR6 front sprocket did you use with the NC23 rear sprocket?
what chain did you use?
did you upgrade the front brakes? mine has braided lines all round but still the NC23 callipers.
Which engine mount bolts did you use? NC23 ones tad short, CBR6 ones too long.... but can be cut down/re threaded.

Lloydie and Woodie have done 23's with the jelly mould engine.
You could just buy mine.
viewtopic.php?f=75&t=43481

Sadly my budget doesn't stretch that far

Good to know that 600s can be put in to the NC29 :)