Hey Paddy!
last summer I was in the same situation as you and got the following message from Julian which was very useful:
“try the fuji shop on ngyuen hue, east side of the street, about a block up from the riverside. they’ve usually got various refrigerated 120 fuji films”
It is a good photo shop with huge Fuji billboards. Very near the Hotel de Ville.
good luck
tiane