So I've just calculated my Legacy value by adding up the non-time related MMs and used both of the above optional weightings and come up with a grand total of 3249.
It's probably worth mentioning that I used a decimal for "No of years service". Just to be clear, I have done 9.49 years of Boincing for example so I get a 9.49% bonus.
If anyone wants to compare that's fine but without a rank it's pretty meaningless, so if you all want to post your Legacy values here ....