Just saw your questions on the Sig Kougar. One change between the original Kougar and the Mark II was that the attachment of the wing was a little different. On the original, the bolts went through the foam and were reinforced by 1/16 ply scabs. On the Mark II the wing had spruce tapered trailing edge stock glued to the wing trailing edge, barely wider than the fuselage and it was through this spruce tapered stock that the wing mounting holes were drilled. The original Kougar was first advertised in RC Modeler in September, 1975. The Mark II was introduced about January, 1980.