TW-Brian is wise. He helped me along with my kickstarter with instructions and advice. I had the "kit" but you are actually in better shape, your '91 engine already has 98% of what you need.
No drilling or swapping cases either. Already have the pop-out on your '07 case where a kickstarter
SHOULD be.
You'll need a new gasket like Brian said and the little plastic plug to cover the kickstart spline. Keep it clean. That's pretty much it
I do a lot of ordering through Babbitts On-Line but Revzilla, Tucker-Rocky, Yamaha on-line or your dealer can get these parts easy. Mine came in 3-4 days. Good Luck.
Gasket-Kicker-Kit.
Gasket, really all you need if the rest of the Kick-Start mechanism is in working order.
View attachment 188786
Installed with the exception of the little plastic spline plug. The one on the '91 will probably break.
Not to worry, they cost $3.49.
Go kick-start your bike.