Rhonda asked in one of the comments for a tutorial for the neckline on the top, and I'm a little embrassed to give one as it is just so simple.
It took me a little bit to work it out but I loved it so much I made a paper pattern for it, and keep it in the enevelope with all the other variations.
The piece is the same length as the original neckband piece (which it replaces), but then is 45cm wide (approx 18"), and is just a rectangle without any shaping. I usually cut it on the fold, but have made the whole piece in case I need to cut it single layer. This does alter the cutting layout, but doesn't cause me too many problems as the collar and front are on the fold, but the sleeves and back are not (as I have a centre back seam).
This works as its a scoop neckline that's not too deep, so the collar goes over my head with ease - in fact the paper tissue goes round my head fine. The collar is already double in construction, and then is folded over again when worn. This gives 4 layers of knit round the neck, so check that is OK from a fabric thickness perspective and your own personal comfort. In UK Autumn and Winter this is exactly what I want, and replaces the need for me to wear a big scarf (pashmina style) draped around my neck all the time, but may be too hot for other people/climates.
When I come to attach the collar I do the following construction order
1. centre back seam
2. shoulder seams
3. collar centre back seam, to make a tall tube, then fold this in half, WRONG side together.
4. quarter the neckline, quarter the collar and pin on the quarters, keeping the seam at the back - stitch collar to neck starting on one shoulder. Serge.
5. insert sleeves flat
6. sew up sleeve seams and side seams in one go.
7. cover hem the hem of the body and sleeves.
I have coverhem, sewing machine and overlocker (serger) all threaded up in dark brown right now, so maybe should sew a few things which need that colour thread!