My cars 100,000 service is due?

Hi All, What should I be replacing or checking on my k11's 100,000 mile service, I could give it a basic service but is there anything else I need to do example replace the thermostat as I don't know when that was fitted last and the radiator is looking old as it is probably 24 years old. I had a major service done at 94,000 last October & had the clutch replaced in February this year. And I'm using 15w40 oil which my mechanic told me to change to 5w30 , which is weird as the MSC quote 10w40 oil . yours Peter Rowley
I would just do the basics. Oil (10w40), spark plugs, distributor cap and rotor if there never been done, check the pcv valve and vacuumhoses and replace if needed. Flush coolant if that hasnt been done in the last 5 years and replace the brake fluid if that hasnt been done in the last few years.