John, I have had good success making sharp turns with glass by using multiple layers of 1.5 or 2 oz. glass.
This is what I would do: Cut a 4" strip of the thin bias cut glass, long enough to cover the stem. Wet the stem with epoxy and let it set till it tacks, apply the glass to the tacky epoxy being sure it conforms to the sharp angles well. Carefully wet the glass, squeegee excess and press the glass into the corners. When this thin layer hardens, check for bubbles and cut out any you find. Then feather the edges with a scraper (razorblade works good).

You are now ready for your main layer of glass. After wetout, cut the glass at the stems back from the stems a little, so the main glass layer does not cover the stem. At this point the only thing covering the sten is one thin layer of glass. after the main layer hardens to green stage, feather the edges and repeat the thin glass bias cut strips over the stem overlaping the main layer. I would use at least 3 more layers of the thin glass strips at the stems making each new layer a little narrower than the last so you don't have any thick edges to build up.

I just used this multiple layers of thin glass method to cover thigh brace wings that I added to my cockpit. The thin glass conforms easily to all curves and does not pop out from sharp corners. I used 2 oz. plain weave glass and have also used satin weave with similar results.

Good luck,

Larry C.