Six Degrees Of Steve Martin

Someone did a bunch of searches trying to connect Steve Martin to various musicians. Some of the connections worked and some didn't. I added some data so that they all work.

Each route starts with  "King Tut" which was recorded with Jeff Hanna of the Nitty Gritty Dirt Band.  I like to mix things up a bit more than that, so I want to add a few more Steve Martin tracks, but I'm having trouble locating precise personnel information for tracks he has recorded.

I am especially excited about the idea of getting the personnel information for Steve Martin's cover of "Maxwell's Silver Hammer" from the soundtrack of the late 1970s movie flop Sgt. Pepper's Lonely Hearts Club Band which starred the Bee Gees and Peter Frampton.  It is probable that the drummer on that track is Bernard Purdie whom I've written about before. (Seriously, go watch the video in that last link if you haven't. It is my absolute favorite non-Sesame Street YouTube clip.)

Unfortunately, I can't be certain from the album credits alone that it is Purdie playing the drums on that track.  (The track, by the way, is terrible, but we don't discriminate on the grounds of quality here at Music Routes HQ, much to my girlfriend's chagrin.)   You can look at a scan of the relevant part of the album artwork in the fourth album artwork image from the top on a page at the awesome Discogs site.  In nice big letters near the top right, you can see that it credits Bernard Purdie with drums and percussion.  But keep looking further down in the smaller print below "Special Thanks To:" and you'll see that David Dowell and Jeff Porcaro played some drums on the record as well.

How can I determine which drummer played on this cover of "Maxwell's Silver Hammer"?

Jeff Porcaro was the drummer in Toto and a much sought-after studio drummer before his untimely death.  But...

Who the heck is David Dowell?

I can't find anything about that guy.