Thanks for all the replies so far - and - comments / suggestions taken on board.
I have looked at such as the 'Defender' on ebay but without knowing what size I am, and knowing how the boot sizes align with other boot sizes I don't want to buy 'blind'.
I am a size 11 in my Rigger boots (for yard work), I am a size 9 -10-11 in shoes depending in make, I have boots in sizes 10, & 11 so I think it is going to have to be a real 'bricks & mortar' supplier for me.
Totally agree that boots are probably the most important part of kit - without your feet you are going nowhere, you can sleep in a plastic bag in an emergency, you can do without food & water for a couple of days, but without your feet you won't get home.
The budget is not fixed (I am fortunate enough not to be financially restricted, but don't spend money needlessly) and I will pay whatever is necessary, be it £150, £180, or £200.
Unfortunately the home situation means I cannot get-away for a whole day to get to Whalley (180 miles, 3.5 hours each way + fitting time and £75 in fuel).
I can get to Go (1/2 hour away).
I am loathe to abuse 'Go' by getting measured & then buying on line - and even then, are (say) the Altberg boots the same 'cut' as Salomon or Meindl