I don't like some of the things that article suggests that you do to a vintage French frame!
The article is a joke... yet holds truth and in this case the truth hurts. It also burns and stings.
Ultimately, to upgrade a vintage Peugeot properly will require you to spend hundreds if not thousands to have it done well.. and you most likely never will get your money back if you decide to sell it.
I've got a '68 PX10-E and I just keep it lubed, tuned and ride it appropriately.
The route I originally wanted to go would have cost me more than a new Rivendale.
People have squeezed thousands of miles out of Xmart bikes by taking good care of them. You can do the same with a vintage bike. Especially a vintage bike that was made very well back in it's time. However, French threaded bikes require replacement components which are most often very difficult to come by. Ride with care.