You can get an aftermarket basket for those old cr's quite cheap but i reckon you could file that.
The stock baskets are good for couple files, they start to rattle a bit at idle but i reckon you can file that out.
remove it from the bike and use the tang on the opposing side as a guide to keep the angle right,
wrap some sandpaper smooth side down round the end of the file so you're only taking material off one surface and the other is a guide.
New is always best, but a bike gets to a point in it's life where the cheap remedy is often more realistic.