G’day David,
Like with many things, there are many different thoughts on the matter. As there are no standards ‘set in concrete’ acceptable to everyone, I merely used what I see as today’s general perception in the marketplace.
Personally, I believe that tangguh is a ‘guesstimate’ of age i.e. approximately when it was made (were I able to narrow it down to its creator, even better). If I were to merely restrict tangguh to karaton keris, then I would be severely restricting the area from which to draw samples. Then of course, there is the matter of definition of what constitutes a ‘karaton keris’ (deja vu
).
With respect to your example, there are some circles who would refer to such a keris as: ‘tangguh’ Mataram/Tuban ‘yasan’……(whatever).
As for what 'should be', who knows. For instance, 'Serat Centini', held as gospel by many, was only written c. 1815 by literary scholars. There are other such documents which predate this.
Anyway, I’m not here to enter into debate. I opened this thread merely to obtain information. I’ll 'soak in' any information.
Cheers.