Hello,
In my oppinion (in other words I'm just guessing), the protruding bars of these Katars are nothing but the result of the way they were made. Namely the cross-bars were inserted in the perforations in the extending arms and their ends were riveted, resulting the protrusions we see.
I have seen Katars like these with diferent types of blades, diferent levels of decoration and diferent quality of workmanship so I don't think they can be attributed to a particular location or time period.
Like for example the hilt of a classic Kard can be with two scales or made in one piece, or like a Tulwar can have a hilt with a hand guard (knuckle bow) or not.