I had searched on Arthur before but when I did it again yesterday, this very interesting citation came up. It is the November 5, 1965 edition of The Canadian Jewish Review, in the section on births, deaths, marriages and engagements. Under the heading of Montreal Engagements we see this very interesting announcement:
Mr. and Mrs. Mac Schwartz, 1357 Van Horne Avenue, announce the engagement-of their daughter, Miss Phyllis Penny Schwartz, to Mark Raymond Zimkin, son of. Mr. and Mrs. Arthur J. Zimkin, of New York.Here is the image (click to enlarge). Look for the Schwartz Zimkin notice in the second column from the right near the top. It isn't necessarily the right one, but the ages are about right and as I say there are not a lot of Arthur Zimkins. This gives us a hopeful lead toward tracking down another living Rabinowitz line.