You could take the clutch lever itself into any decent MC shop and the can match up the shape and cable end size.
If you are dead set on using a clutch safety switch, then again, yopu can go to a bike salvadge and find a bike that has the switched clutch perch and lever you need.
The key to a clutch is in the length from the pivot bolt to the cable end hole. That needs to be the same or VERY close to actuate the clutch properly. If it is too short it will not fully disengage the clutch, and if it is too far away it can make the pull too hard for your bikes clutch springs. The other consideration is the ball end diameter and length so that it seats in the lever properly.
Not to critisize at all, but why is it that you need the clutch safety switch?
None of my dual sports have ever had one nor has any MX bike I have had. I guess I have always known to check for nuetral before letting out the clutch, and even when I think it is in neutral, I let the clutch out slowly to feel that it IS in neutral before letting it idle, I so not even trust the neutral light on a bikes dash.
Just a thought, and if you feel the need for one, by all means add it.
it is easier to ask for forgiveness than permission