Here is a nice sporty short sleeve shirt by Jantzen. It's a nice gray with almost a touch of greenish and brown in it, and white "highlights" in the fabric . One button in the front. The tag says M, but here are the measurements. (refer to the last pic above to see how I measure shirts)

Shoulder to end of sleeve (including cuff) 9"
Chest (armpit to armpit) 20"
Length 28"

This item is sold from a vintage boutique in Roanoke, VA.