I long thought the jazz thing was an intentional reference. It certainly seems a good fit between the show and the books.
One thing that struck me that I'm not sure anyone else ever noticed was this eagle connection. In a flashback in
Indiana Jones and the Peril at Delphi, when he was fourteen Indy met an old Navajo man named Changing Man, who set Indy on a vision quest on which he would meet his animal guardian / protector. Indy encounters an eagle, and from then on, according to Rob MacGregor, the eagle is his guardian creature, and references to eagles crop up every now and then. In
The Young Indiana Jones Chronicles, the 93-year-old Indy, presumably retired from adventuring, has exchanged his whip for a cane, and the
cane's handle is a brass sculpture of an eagle's head.
Coincidence? Possibly. Probably, even. But
still...
Personal story: as it happens, while like many Indy fans I have some interest in putting together a set of Indy-esque costume gear and prop replicas, it's something I haven't begun actively pursuing yet, with one exception: that cane. By a very cool coincidence, many years ago - around the time the show was still running, actually - I wandered into a pawn shop near my parents' house (I still lived with them then) and happened to see this
very familiar-looking cane. It had a brass eagle's-head handle, and I realized it was extremely similar to the one carried by George Hall's Old Indy on the show. I went back home for photo reference, the pics with a George Hall interview in
Starlog, and came back to find it was indeed
exactly the same style of handle. The wooden shaft of the cane was another story; the one I found was a very light (in color) wood, and also in two pieces (with a joint in the middle of the cane), whereas old Indy's cane is a single shaft of darker wood - but then, "the shaft is just a stick..."
and could easily be replaced. Naturally I bought the cane, and I continue to treasure it to this day. It's funny to think the first "real" item of Indy gear I have* is one of the things he added to his accoutrements late in his life...
*
I have owned brown fedoras, but dissimilar enough to Indy's that I eventually became dissatisfied, and I no longer have one, alas - but I will again, some day...