fixing a frustrating pattern problem

This seems to always happen to me these days: i get to a certain point in a pattern where, even though i've followed the pattern thus far, it doesn't allow for what i want to do with the pattern next. In this case i wanted to make the sleeves on this sweater convertible (that is to say, a vest with sleeves that can be buttoned or snapped on).  Unfortunately, i wasn't quite sure how to do this, and i was in a hurry to get the project done, so i just started the sleeves in the round at the armhole.  The trouble was s a little issue with the sleeve being too baggy. Take a look (the one on top is my solution, the bottom is the sleeve before i took it out):

I'm not sure that you can really tell while i'm not wearing it, but there was excess fabric bulging under the arm even after i reduced under the arm for about 12 rows.  This sort of thing happens to me quite a bit due to my excess bust size and designers not expecting women to have breasts.  So i frogged this back to the live armhole sts (there are 4 sts picked up at the shoulder and 2 sts picked up under the arm) and knit around one complete row with the start of the row as the underarm.  There are 70 sts total, and i have divided with 7 sts on each side of the row marker.

To the right of the row marker i reduced with ssks, on the left side i reduced with k2tog on the right side or p2tog on the wrong.  Inside the markers i knit or decreased only, but for the other 56 sts i worked in a k2, p2 rib.  So to start out, i k5, k2tog, worked in rib until the next marker, ssk, slippped the last worked st back to the left needle (along with the marker), turned, and worked rib around to next marker, p2tog, slipped st back to left needle, turned, work to next marker, ssk, k4.

So it's kind of like i worked in short rows, but instead of wrapping sts i turned at my dec st.  The next couple of sts of rib i made sure to keep snug, but not tight, and each dec becomes part of the next dec the next round, so there are no holes.  I went through the same process again (with less sts around the beg of the row, obviously), leaving 2 sts on each side of the center marker (60 sts).  The decreases created a triangle, as you can see below.  From there, i bound off.

So the armhole is now pleasantly snug.  It looks a little tight in the photos, but it doesn't feel tight at all.  Hopefully i will get some better images up here (or on my Ravelry) soon.  Right now, it needs to be blocked a bit, and then i need to start on the sleeves before it cools off too much (one can only hope!).