Lou Wolgast built a Charles Mackey "Junkers Gobbleswantz" (sp?) ('58 NATS Winner) and flew it in several VSC's. As a HS Freshman, I was enthralled by the magazine article, and talked to Lou about his control system. As I recall, he said he tried double BC's/double pushrods, but found that they bound up some and he abandoned the double elevator pushrods. I expect this was due to angular errors on the horns and/or minute pushrod length differences.
I'm not sure exactly how he had the thing rigged, but I may eventually find out, because it's hanging on the shop wall downstairs! Burt Brokow flew it for awhile, after Lou sold it. Then, Burt sold it at Eugene NW CL Regionals about 10 years ago or more, and I pounced on it. Silly boy! If anybody has the article ('58-'59 AM?) and could scan and email it to me, I'd be grateful! I've got the plans.
Steve