Hi Mark
When I refere to a multi format carrier I mean the folding cast aluminium carrier that holds all the various drop in mask frames from 35m upwards to in my case 5 by 4.
When I obtained the 504 it came with all the different inner masks but no carrier.
I was delighted to obtain the carrier from ebay for 20 which cured my problem.
I am delighted with the enlarger
Norman