Just as a follow up, because the sum total of buying the OEM parts individually was so high, particularly because the parts were only available from different suppliers, nearly all abroad, I took a punt with the duty and ordered the M-TEC kit from Japan.
It turned up today, delivered by Parclefarce, there was no duty, VAT or anything else payable.
The quality seems OK, though I'd need to see an OEM footrest set to compare it with, I suppose the test is how long the plating lasts, I know the Honda ones can go rusty eventually, but how many years and salt baths that takes I don't know. I'm going to try and keep my plating dosed with spray on silicon where I can, as I am going to be riding Candy in all weathers, I don't want her to be a garage queen.
Ironically the OEM bolts (they go through the pillion rests and the exhausts, so are quite substantial) cost more, before postage from Germany, than the footrests, there were cheaper pattern bolts on my eBay watch list, but I forgot until I'd ordered.