As I understood it, your absolutely correct on that assumption. The Speedster came out after I bought mine. I would have most likely bought that model if it had been an option. So, I spoke with John McBean when it was out. It wasn't but a passing question to him but from what I understood him to say was, My Series 7SS was the same plane with the exception of those items you mention regarding the gear. In addition, the wings are shorter as well. That meant I could have converted mine anytime I liked. Swap to the Tapered Grove gear and Tires and build myself the shorter wings. Viola I have a speedster. Oh, the empinage was also built with the wood ribs as does the Speedster.