Cambelts unless they've been done recently. Fluids, tires, the usual stuff.
Main thing: Do Not Let It Sit And Rot.
These do best when ridden regularly.
Do the maintenance.
Don't do silly mods.
Ride it more.
I had a '93 M900 Monster, so the same basic mechanical package.
I rode it daily for 24 years, and 265K miles, and I wasn't done with it yet.
It got taken out by a minivan last year, otherwise I'd be looking to turn 300K pretty soon.