Wow, that turned out great! My understanding is the snugness in the arms is what helps keep the body from raising when you lift your arms (snug as compared to the cut of a T-shirt, at least). Unless there is something called the 'grand aissette' (I've butchered the spelling...), which is how the Revival gambesons are, with that "circular" cut look to the sleeves.
Congratulations on the new gambeson! Now the question is ... will the first thing to grungify it be the mail, or Sir Brian and I with our grubby gauntlets?
Also, I do notice a distinct lack of green on it. Perhaps that can be taken care of at next Friday's event...