Hey sinthros,
I hope all is well...just to follow up was able to unlock those Bengals uniforms just by adding in the extra lines on the MixMatch DB within the Fifa editor for M22. So, if anyone asks, they just have to make sure the options they create on the mixmatch file have all the required items assigned to them in order to get it to work properly in the game (or else you'll have an invisible team on the field)...you need a helmet, jersey, pants and shoes for each kit you have listed on the mixmatch file. Note, black on black shoes being assigned will give you an invisible team too for some reason...because EA...I guess. i can send you the project if you're interested in seeing what i did.
--Ninja