The tale of the Jack Tar can be found here in gloriously illustrated and annotated PDF form.
Not sure who the OLSEN person is; the back of the card says it's from Loiuse and Charles. (Louise seems to have added her name after Charles did his big john-hancock routine and left her out.)
The "gang" was the crew from Pharmacy Sales at Williams No 1. Googling about brings up this history page: "you're Old Waco if you ever went to Williams Drug."