The one shown below is for August '72 to April '74. Chassis # 213 2000 001 to 214 2164 059. VW part number = 211 953 509 H. SWF part number = HLS 291 096.
seems that the '73 is a difficult year for indicators http://www.thesamba.com/vw/forum/viewtopic.php?t=532275&start=0
Here is the link to the NOS ones. hope you are sitting down. http://www.aircooled-museum.com/achat-t2-72-74-turn-signal-switch-21738.html
The repro version was £127 when I bought one from VWH and it was rubbish. I gave up and fitted one of these: http://m.ebay.co.uk/itm/UNIVERSAL-S...MINATED-GREEN-180039-/181259450321?nav=SEARCH A bit of modification was needed, but not much. I had to wrap it in tape to avoid horn issues as well. Functionally much better than the repro version and loads cheaper.
Would £25 posted seem out of the way for one of them unicorn paddles? If it sounds reasonable, and it helps you out, I might have a spare. I'll plug it into my bus to make sure it's all working when I get 5.