I too find this topic very interesting as a new collector of these arms.
What strikes me about the tulwar hilts that we commonly see is that there are a limited number of features which can be mixed and matched, but which somehow must provide some reliable information if only we knew the history of the pieces.
I wonder does anyone know if there has been anyone working on morphometric studies of these perhaps in a similar way to cladistics in taxonomy? Such an analysis would always be reliant on good provenence (and messed up by the kind of battlefield collecting and subequent armory marking mentioned by Jens), but given enough material might be able to create some generic rules. Maybe this kind of study has been applied to other weapon groups already? I would imagine it would work well for Indonesian weapons too since these seem to well understood in terms for form and tribal origins. Just an idle idea from a biologist
