Very interesting! So it looks like my Peugeot tandem is a 1980 model.
I've tried dating it on the frame number: 801 0000 384, but I understand that is sometimes impossible to do! I've checked the original rims and hubs and they are date-stamped 1978....so that would tie in with a 1980 model.
I must get on a finish my blog! I've had the tandem a year now and because my stoker has been busy, we haven't taken it for a test run yet!
Have fun with your machine betterdays and look forward to seeing more photos of it.