First, I washed and dried the linen, then cut out the necessary parts (NB the cuffs or sleeve bands should be small for this period, 1" or so when finished).
Next, the side seams were flat felled, a good intro is here:
http://www.midtown.net/dragonwing/col0006.htm
Sleeve tubes were sewn together with a back stitch, then felled, underarm gussets applied to the sleeves.
Then the sleeves were attached to the body (shoulder straps being pinned in).