Placing the spare on the driver side allows for a better view thru the rear view mirror, and, when the driver is looking back. The spare is behind the driver on an original '75 for left-hand-drive USA 40s. So it sounds like the license plate needs to move to the passenger side on the '71 swing-outs, or the spare needs to move to the passenger side, and the tag light wiring moved to the driver.
Also, I forgot to mention that on my '75 I open the passenger side door and I have access for cargo and passengers. The latch on the swing-outs is on the driver, and it needs to get out of the way to open the passenger side, IIAC, so for every time access you will need to open the spare tire carrier and the driver swing-out, or replace the latch set-up with a mirrored image one like the latch that holds the '75 and '76 spare tire carrier, or factory soft top tailgate.
I considered the option of a rear steel single-wall stamped 'tailgate' panel as a start for a pair of barn doors for my '75. That way I can avoid the inevitable rust that all these doors have, not hack up a Toyota original part, and place the later type two-lamp style license plate frame and lamp on it. It would look homemade from the inside, but probably quite convincing from the outside, aside from a few details. Plus, if I fabricate it, I can burn in some provision for a door-stay (probably just a removable steel rod), because, on not-level surfaces, or windy days, I can never seem to deal with the one door wanting to close and moving cargo at the same time.