Vintage Peugeot conversion help and tips please

The Pug will have a 1" fork and headset, and Im pretty sure the Charge whisk forks are 1 1/8".
You can pickup up a new cheap 1" fork off ebay for £15 delivered (just get the right steerer length).
You will also probably need to change the headset, as the thread size is likely to be different (1" tange for under a tenner).

if its an old pug then it also might have a 22mm stem, not 22.2