To describe sleeve head curve:

Join straight guide lines, for armhole, from 29 - 34 and 10 - 35.
Divide guide lines into 3 equal sections and measure reference points, 0,3 and 1cm to either side of these lines, as shown in diagram. Draw new curved armhole lines to equal original armhole measurements on front and back body blocks.

Trace off sleeve and yoke areas for front and back;
Front points 24, 31a, 32, 34, 29, 30, 25, and 24.
Back points 8, 31b, 33, 35, 10, 5, 0, and 8.

Join Front and Back overarm / shoulder lines from neck points (24 and 8) to wrist points (31a and 31b).

Ammend Back Balance:

Trace off remaining section of back block.
Square up 1.5 cm from point 5, on centre back line.
Square up 1.5 cm from point 36, one third measurement 10 - 5.
Join ´new´ point 5 and ´new´ point 36 with straight line and extend gentle curve to point 10.