Jacket from shirt pattern

OK, I"m hot on the trail of a chinese jacket like I just saw in "Koos and
the Couture ??????" book. Don't remember the last word.

Its on page 45, upper right hand corner. I'm going to adapt this to
something more masculine if possible.

I have a shirt pattern that fits me. I was told I need to drop the bottom
of the armscye, and add about 4" to the girth for ease.

That redrawing of the armscye has me jittery. How much should I drop the
armscye, and how much does this translate to in adding diameter to the
sleeve. I know how to split the sleeve pattern outwards to gain diameter.

Or, can someone point me to a good chinese jacket pattern for guys?

Dwight