Hi Jens,
Simple answer is that I have no idea. A floral hilt on what we think of jamadhar with arm bars makes no sense.
Like you say, we dont know if it was so. We have multiple terms in English translations apparently used interchangeably (katar, katara, khanjar, jamadhar, khapwa). We still don't know if the term referred to specific handle type, blade type, curvature, thickness, or entire ensemble. The use of these terms seems to have changed over time place.
Maybe katara referred just to a narrow blade, slightly curved. Maybe not. Like most things, there were probably qualifiers to denote more specific uses (ex. slashing knife, stabbing knife, dagger, punch-dagger, etc...).
Based on the sources at my disposal, my thinking was that the term phul-katara matched a dagger that has a narrow, piercing, slightly curved blade, and some form of major floral hilt. Could be jewelled or not. Ivory, or other material like jade/nephratite.
Unless we go to the original texts and associate them with period illustrations, we know nothing
Then again we have the Ain-i-Akbari in Urdu, and the Tuzuk-i-Jahangiri in Persian covering matters in the Mughal context.
What do we have from the Rajputs?
Emanuel