Pak Boedhi has given an explanation of his understanding of the roots of the term "kalawijan", applied to this keris type. However, there is another meaning to "kalawijan".
"Kalawijan" is from "kalawija" which is a variation on "palawija", and "palawija" can mean the second, dry season crop, or it can mean the deformed servants who used to be maintained in Javanese royal palaces.
Since this keris form is clearly a deformed keris, I would suggest that perhaps the second way in which "kalawijan" can be understood may be a more appropriate application than the reference to a second crop.
However, it can be easily understood how reference to them as a "second crop" could also be valid.
The term "owah-owahan" is more a description of this blade type, than a dapur classification.
"owah-owahan" means "a change".
These blades are also referred to as "robahan", which again is Javanese , and also means "a change".
In Indonesian this would be "ubahan", or the more usual variation of this same word:- "rubahan".
In my experience, most people refer to blades like this one as "robahan", which once again, as with owah-owahan and ubahan/rubahan, is a description, not a dapur.
In fact, all these ways in which to refer to these types of blades, are descriptions, rather than dapurs.
When we say that a blade is this dapur, or that dapur, what we are saying is that the blade conforms to a certain set type. That set type may be interpreted differently by various people, but pattern books held in palace repositories should be taken as the final defining authority on what is a legitimate dapur, and what is not a legitimate dapur.
Quite simply, if a blade form does not appear in a palace pattern book, it cannot be said to have any dapur.It has become "di luar pakem".
Yes, there are two claimants to the throne of Surakarta Hadiningrat.
This problem arose because Pakubuwana XII never named a first wife, and because of this there can be no successor on a basis of tradition.
The two claimants each have documents to support their claim, and one has possession of the Kraton and has been installed in the Kraton as ruler. The other ---who appears to have been a little too much of a gentleman at the crucial moment--- has had himself declared as the new ruler.
This link will give an overview of the situation:-
http://walah.multiply.com/journal/item/32