Can I ask what one normally pays for this sort of service? In particular the valuation as I've been recently given one of my grandmother's diamond rings and need to put it on the insurance. 

Yes! I’ve used Georgina Boyce recently to value some rings and repair my engagement ring. She’s lovely to deal with and is very experienced. She’s based in the Tonsleys. http://www.georginaboyce.com/about

I have inherited a Sapphire ring from my Grandmother which I believe is more than 100 years old. Can anyone recommend an excellent jeweller who could provide a valuation and clean/restore it?

Thank you.