What scratchplates will fit a squier strat? Apparently the 11-hole fender standard styles don't fit so any idea where I can get one that will?
Some might fit. You can drill new holes to match the pickguard, and the old ones won't be seen.

Otherwise, I'm pretty sure yuo can buy pickguards with 5 or 7 holes, or buy raw pickguard material and make your own.
I don't trust myself to make one, why would the websites say they don't fit if they do?
Take the old one to a plastics shop and get them to cut you a new one? Shouldn't be too expensive for just a pickguard.. I know you can get glass and mirrors cut to size like that. Pickgaurd shouldn't be any different.