OK, now I am really enthused!
It appears that Hopmans is the name of a bike shop (and their racing team), and that these bikes were made by...
Ciöcc !
(just as for the Concorde brand) So, that's pretty cool.
See here:
https://www.reesfiets.nl/product/hop...corpione-61cm/
Now, if anyone has complementary (or contradictory) evidence, I am very interested.