Ordered it from Amazon. See here
https://www.amazon.co.uk/dp/B0CCMTR558?psc=1&ref=ppx_yo2ov_dt_b_product_det...
It came yesterday but it did not quite fit our sink (although it is supposed to be UK standard), maybe because our sink is 70 years old.
They refunded but did not want us to return it ...
kitchen sink strainer (Sopwell AL1)
This offer has been gifted to someone and is no longer available.