a greeting card lending library?
that sort of sounds like fun.
(makes me imagine things that seem culturally unlikely,
though i was born shortly after the war myself)

there's so many things mashed together, even with separators.
did aetna life run a book store,
or a book store sell life insurance, along with war bonds?

or did aetna pay printing cost for book store advertising book marks to put their own name on them too?
(that seems to my mind the most likely - but far from certain)

a very different era, when printing was more expensive then paper.
(because the technologies of printing were labour intensive and the equipment itself, large, heavy and clunky most of it)

My guess is that the then-HQ for Aetna is there as a local landmark, with no other connection.

Witkower’s, under many names, was around for a long time, and I imagine the lending library — for books only! — was a 19th century holdover, when printers sold books, and lent books to get folks book-conscious.

Hartford’s community was pretty tight in those days, and cross-promotion seems likely.

Five-digit (9-9999) telephone numbers, no letter prefixes. This pattern would have been used through the war; we would start seeing 7-byte numbers (XX9-9999) in the larger Connecticut cities around 1947. In the early 1960s, Willimantic and Storrs still used name coding. HArrison 3-9999 for Willimantic, GArfield 9-9999 for Storrs. I think they went to 3+4 around 1964: 423-9999 or 429-9999.

BUY U.S. BONDS AND STAMPS That implies it was wartime.

They used the Witkower name from 1929 to 1960.

We still had the EVergeen exchange when my family first moved to Old Saybrook in '65, though by the time I was cognizant of my surroundings and knew my phone number (ca. 1971-2), that had vanished. Saybrook went automatic-dial, I think, some time after the War.

The bonds and stamps reference was what made me think it was war-era. I think "war bonds" started to be used after Pearl Harbor; they were called, I think, "Defense Bonds" before 12/7/41. Hard to say exactly what year this would have been, of course. No © notice.

That bookmark's in great condition (well...it was wedged in a book but still...)