I've never actually tried the combination, and haven't had salad cream since childhood... but it tastes quite like tartare sauce so I'd have thought it was a good combo - like the classic fish sauce but without suspicious green bits.
I wish my DD liked fish. She used to love fish fingers as a toddler but now she can barely stand the smell of fish without retching. I think they must have had some nasty fish for school lunch when she was wee. 
I really ought to get some fish fingers for myself anyway... which ones are the best?