Being German myself, I strongly object to the permanent introduction of another stereotype German villain. :)

: B. Have other pulp heroes drop by! Tom Swift, Doc Savage, and
: Young Indiana Jones come to mind.
: C. Have actual historical characters from that time period drop by. Frank Buck&Clyde Beatty, USMC Col. Chesty Puller, Al Capone, and
: Texas Ranger Frank Hamer come to mind.

Maybe it's just me, but I'v always thought that the introduction of many actual historical characters was much too often an easy way out for scriptwriters who couldn't come up with interesting characters of their own. If we would go down the road that you suggest, I fear we would even further move away from any sort of Lost World continuity, that so far is sadly lacking. Just my thoughts.