Standard Libelle in a Cobra Trailer

A friend of mine bought an 85 Cobra that used to hold a Ventus and is
in the process of fitting his 201 Libelle into it. The horizontal
stabilizer holder that came with the trailer is nowhere near the right
size for the Libelle part so we're faced with the choice of either
making or purchasing a replacement. The Cobra website lists a variety
of gliders to choose from when buying the part from them but has no
listing for the Libelle. It does list some standard class gliders from
that era such as ASW-15, Standard Cirrus and LS-1. Does anyone have
any idea which bracket might fit the Libelle stab? I've seen Libelles
in Cobra trailers before so someone must have already figured this out!