Ididit Univ.Colum

Perhaps you've tried, but have you given IDIDIT a call? They do make a universal adapter, I'm just not sure if it will work for your purposes.

Both Flaming River & Grant make adapters for a 66', but I don't like the idea of mixing brands and it may not work anyway.

Unfortunately, all 3 are pretty vague in their product description.

Good luck in your quest.