Hi Pilip
No the book spec for the wall thickness has not been changed
If you can get some pipe that has a wall thickness of at least 3mm & the OD is 130mm, that should be ideal for the job
My 5" pipe just happened to be off-cuts from my suppliers standard stock & has a nominal wall thickness of 5mm .... Could have got 5" with a wall thickness of 3.25mm but would have had to buy a full length
What you have found should be fine & will save the extra cost of obtaining from the UK.