My husband had my slider on 2 board bags replaced at a boat place in Mornington - in the industrial area, for $20 fixed the whole issue and i was thinking the zip needed replacing, but the new slider did the trick.......when my husband isn't as tired & grumpy (

)he might remember what place it was and i can let you know - not too many boat places in the industrial estate in Mornington though if you ring around......