Welcome to the forum. You'll love it here!

You probably aren't going to find a strainer with that hole pattern. I would just use whtever you want and leave or cover the existing holes. You can use wood filler, dowels or even a quick fix is to cover them with the original screws and nuts, with larger washers on both sides (don't overtighten). Not the best looking fix, but it's quick, easy, cheap and "reversible" (if you want to put the original strainer back on later), especially if you keep the strainer near you, as most drummers do. If only you can see it, who cares?

Since this isn't a 1950's Supra and is "just" an MIJ, it's not like the value will go down because of non-original equipment. Use a strainer you like, make it playable and have fun with it! That looks like it has a pretty decent snare bed cut already, so it should tune up real nice!