You need to look here regularly, Stephen:
https://www.two-sixties.co.uk/mgoc26...-260s-FOR-SALE
The list is updated several times a day searching over more than 40 web-sites, forums, FB groups and publications world wide, so as "Complete" and as up to date as we can make it!
Forum Members' cars offered publicly for sale are also listed of course, at present including this very nice one in Yorkshire:
https://www.two-sixties.co.uk/mgoc26...418#post188418
In view of the scarcity of good cars, it may be better to find the car(s) you like best first though, and worry about the 'where' afterwards!
David