Your welcome Phil,
In the week after I sent you that link, I found at least three more on Ebay. They all looked real nice. One must have been the one you got. Ebay is like that, you can't find something for a long time, then all of a sudden many appear.
I don't know how much help I can be with the plane but my copy of Ron Moulton's book "Control Line Manual" has a small photo of the DeBolt Special. The caption says "First of the DeBolt Specials with fixed u.c. and ignition Hornet 60, made 120 mph with clock wise rotation in circuit, was the first to crack 100 mph". Unfortunately, there is no plan but below the photo is a small plan for the DeBolt Speedwagon 50. The wings and stab look about the same. I think a person might be able to draw up a plan from the photo and Speedwagon plan.
Let me know if you would like me to scan the page and email it to you.
A while back, I got my hands on a McCoy .29 Red Head (Dick McCoy's rear rotor job) and would like to build a vintage speed plane for it. I still haven't decided which one, maybe a Speedwagon or a Whirlaway.

Orv.