A Duncan 15 trick Silver Award star patch, likely from around 1954 to 1955, or 1952.
The three different star patches in this series -- 8 trick Bronze, 15 trick Silver, and 22 trick Champ -- are unusual because they were constructed out of heavy felt and machine embroidered. Whereas, the dated 1953 Duncan star patch set was constructed of heavy gauge cotton cloth and embroidered. Why the difference is unknown and why this trio of patches does not have the year embroidered on them is also unknown.
These felt-based star patches are susceptible to moth damage and typically have slightly off-centered border stitching.