Since the post I've come across a name that I'm sure is the artist - Gerald Lazare. This thanks to the invaluable Index of Canadian Illustrators which has the short description - "Comics artist employed at Bell Features [source - John Bell, Collections Canada]". Bell Features published Canadian comics in 1940s and early 1950s.
Here is another cover from the Lazare, this time signed as "GL". The close resemblance between the men, including the type of mustache you don't see today, is obvious.
Harlequin 63 - July 1950
Harlequin 64 - July 1950