A big motorcycle shop on the side of the highway might have it, it might not be hjc so we cant say it will work, because HJC visors fit perfectly with some slight bending, but the helmet resin and fiberglassed will hold the visor in bent that way. then you just need to push it into place and hotglue or secure it some other way.
If you get it in a motorcycle shop, buy a big visor, bigger than you think you need, because you need to cut it to fit, and if you get one thats small, it wont fit after being cut.