Vintage Peugeot conversion help and tips please

Go to your LBS, find out what size seatpost it is, chance are it'll be those usually small Peugeot sizing (23.4 I think), the good thing is that Decathlon sell a seatpost that come with shim to fit various unusual size and cost something like £10 and will fit your Peugeot.

http://www.decathlon.co.uk/EN/l330-basic-diam-23-4-25-27-2-35412401/

So not all is lost in finding suitable seatpost.

that's excellent, thanks. I still need to get the old one out though.. I would imagine there is alot more material to fizz away with hydrochloric than a usual one? Still do-able?

I should probably have searched that one.