In the 1960's , a Ruana knife was something of a novelty compared to a Randall, Loveless, Draper, etc., because they were crude in comparison. It was many years later that the tables turned. Rudy Ruana was recognized as a one man giant in folk art knife making. Even his crude signatures made with an engraving vibrating machine is now considered to be more valuable.

It is possible that your Bowie was before Rudy got his engraving machine and before his first stamp. Not impossible. You don't show the thickness of the blade, which might be a better indication, since Rudy tended to go thicker than thin.

Pap