That was the first time I actually knit something planning to do a cut and sew and, for future reference, I'd leave one or two needles out of work at the centre - I did hang yarn marks as I was knitting but, after the fact, realized that a needle out of work would have been more effective (and easier - I'm all about that!) because it would show the centre line on both inside and out.I used the outside seaming techniques from 'ManFriend Hoodie' for the shoulders and attaching the hood to the neckline.
The finished garment - I soaked it in Eucalan for a half hour and then in fabric softener for another half hour, rolled it in a towel, laid it to dry and then gave it a final block/steam (which you will have to do with any fairisle garment made of pure wool whenever you launder it ;-)). The yarn softened up but it is not quite 'next-to-your-skin' wearable even though I have never had a problem wearing pure wool before but that's okay - it is more like the weight of a jacket anyway. Love it!