Mine is a 71 too. I'm in Alberta and to pass the provincial inspection recently, (it came from Winnipeg Manitoba) I had to reinstall the turn signals. The turn signals were a requirement here effective Jan 1, 1971. My wiring harness was well molested over the years and included a four pin trailer hitch connector amongst other things. It was easiest to just gut it and start over. If your wiring harness is intact or close to it you may get away with just plugging the signals back into the harness. If it's a mess I'd buy a new harness. They weren't expensive and install easily with a minimum of fuss.
May the Lucas gods smile upon you!
Cheers,
Simon.