Horton/Robertson differences

[JimC]

I think I found a partial difference:

All Robertson kits came with tail boom fairings. Some Horton kits had tailboom fairings, and you can purchase tailboom fairings without either STOL kit.

So from logic 101:
If it doesn't have tailboom fairings; it doesn't have a Robertson kit.

Can anyone find an example where this is false?