Then to find out if this is the case the question should be asked in the C&V forum to find out if this model of Peugeot is one of those rare birds.

It also brings up the idea of just cold setting (carefully bending with lots of measurements to ensure the legs stay centered) the fork legs to open the spacing up to accept a regular modern wheel. Instead of trying to find or fiddle around with special spacers or bearing cones it seems like this would be a far better long term solution.