That's not a "73 Sun Bug."  It's a 74 Sun Bug.  You can tell it's post-73 because of the bumpers . . . and 74 was the only year for the Sun Bug . . . although all the stuff that made it a "Sun Bug" was avalible earlier and later than 74 . . . except maybe the paint.  I think the Sun Bug gold was a 74 only color . . . and there were two different colors . . . and neither weathered very well.  If it has the original Sun Bug wooden shift knob, the knob is worth as much as the rest of the car!

The shift knob and a Sun Bug deck lid emblem were not factory installed.  They were supposed to be installed by the dealer, but a lot of them weren't.  They are pretty rare these days.  I saw an original Sun Bug shift knob go for over $400 on eBay a few years ago.  I haven't looked for one lately, but I don't imagine they've gotten any cheaper unless someone has reproduced them.