I'm a bit curious as to how you sent the Pacemaker 59 back to the factory....my Dad was the designer and manufacturer of this engine, around 1947, and I believe that operation was wrapped up around 1950-51 or so ( I was only 7 at the time!). Did another company takeover the design and distribution? I'm stunned that there are still quite a few modelers who remember this engine. I converted one to glow (couldn't deal with ignition engines at age 9) and used it in several control line planes. Subsequently got a Fox 59.