Here's a black OS Balance with a 5-point Star emblem between the top of its 14K clip and its White Dot, and a wider than Autograph 14K uninscribed cap band.

So far, we know there's 4 Sheaffer's OS Balance Star pens:
1. R A Thompson / Hobart Star Club / 1941
2. Walter Young, Hobart Star Club 1938
3. H.C. Belore, Hobart Star Club 1938
4. Uninscribed

with postcard showing Sheaffer factory in Fort Madison and postmarked 1939