GURPS supplement for Poul Anderson’s “High Crusade”?

Recently I’ve been re-reading the amusing novel "The High Crusade" by Poul Anderson and enjoyed it as much as I did back then.

As I was reading, a thought came to my mind: I seemed to remember there was a GURPS supplement detailing this setting and was determined to find it.
So I searched the web for it but all I was able to dig out was this board game (whose cover, I’ll acknowledge, rings a bell), which cites Traveller, not GURPS.

So I wonder: was there a High Crusade GURPS supplement like I seem to remember or am I completely wrong?
And, if there was any, would you please link me to a review?
I would appreciate that a lot.