Sprocket wear is fairly easy to see, the service manual should show it, but maybe grab and 350x or 250r one for a bit newer manual with good diagrams and such. Basically the points of the sprocket should be straight, and the tips shouldn't be sharp. If you've seen a new sprocket for the typical atv chain size, you've probably noticed how wide the flat is. I can't remember off hand if just when it's pointy is when it's considered worn out or what, but I kind of think that's the case.
Cheap/junk sprockets are likely mild steel or not treated, the quality ones seem to be hardened though. If you can do the heat treating your self (not super hard), you could heat a normal front sprocket for something and make it loose its heat treating and machine the pipe section of the sprocket and make the two go together. Might be a fun project for you to do. Not sure how hard the actual sprocket points are to machine. I suspect if you have access to the machines that do that kind of machining it should be pretty accurate.
I suspect you don't live near Michigan for an easy access into the states. I'm quite far from the Canadian boarder but could be an option if you wanted to make a vacation out of it or something.
There's a company called sprocket specialists, maybe they can get you the sprockets for a reasonable price. My dad bought their custom sprockets for a 350 warrior that we ran 28in mud tires on the back, so 1 tooth smaller front than what's available, and like a 52 tooth rear, biggest I think was 48, stock was like 13 and 40 lol. Anyway, we mud bogged and abused the snot out of the machine for years and years and they are holding up just like the OEM sprockets, we kept getting the aftermarket ones that the tips wanted to bend and the chain always came loose fast like it wasn't machined for the right chain size.
Here's their site: https://sprocketspecialists.com/