Ja-Do was the unpromoted line from Duncan in the 1950s. The name came from a compilation of Donald Duncan Sr's sons, Jack and Donald, or "Ja" and "Do".
This patch came attached to a sweater, with a number of other yo-yo patches attached. This is a larger patch at 5" in diameter.
I had been looking for this patch for years, and had a number of discussions with collectors that insisted it did not really exist. Well, here it is ...
