Originally Posted by Dave Noble

Allowances are as per significant carrier from check in to point of collection, so the allowances will be different

The allowance for DUB-LHR will be BA's baggage allowance, which is (for economy) 1 piece of max 23kg or 2PC of max 23kg for business class
The allowance for LHR-PER will be QF's allowance which is 30Kg/40Kg/40Kg./50Kg for economy/premium economy/business/1st

If you hold status with OW , then that will be available on top of the Qantas allowance but no additional allowance on the flight from DUB

Originally Posted by Dave Noble

It doesn't - for Europe - Australia it applies from check in to baggage collection - if this was a journey to.from US , then the US rules would apply which would mean that the baggage allowance of the governing carrier that existed at the start of the journey, would apply throughout

if there was no stopover and bags were checked from DUB-PER, then the MSMC allowance would apply to both sectors and so the allowance would be 30/40/40/50 ( but no status benefit ) for the whole journey