I own 2 Longstaffe paintings, both 'winter woodland' scenes of Essex. As far as I know, neither was reproduced as cards.
Apart from Tuck's, he also painted prolifically for Hildeshimer (sp?) who produced greetings cards in America.
His style suggests that he didn't spend a huge amount of time on each painting, so he could easily have turned out several hundred.
How many still exist?
215 paintings altogether
Over 1500 paintings.
over 60 paintings
over 1000 paintings and 8000 drawings
15,036
one
215
279
990
There are six paintings of this title, but no two are alike.
charles condor drew 41 paintings
30000