From searching, most of the similar-year Yamaha locksets seem similar (as individual parts) to the Seca II part, and since the XJ600 Seca II/Diversion full locksets are not as cheap or anywhere near as plentiful, I'm wondering if a swap works.
Seca II

98/99 YZF-R1

97-00 YZF600

Heck even a 07-15 VStar 1300 has similar hardware

So the question is - what will fit? Anyone know/have experience with these parts?