Hmmm, I am getting a bit confused (must be a double post over on SSW!).
Anyway, I made a Sterling Ring Jr. some years ago. That wing is a C tube wing (like the S1A). I guess (according to Mike's description), the Estes version of the Jr. is more like the "Sr." Old Time RIngmaster S1 with a 1/4" or so square leading edge (sanded of course to an airfoil shape).