In search of a better looking radiator cap, I tested a Mylers earless 23PSI one made for Japanese bikes. It fits just fine.
Link: https://www.amazon.com/Mylers-Earless-Pressure-Radiator-2001-2018/dp/B078SK42QZ

Link: https://www.amazon.com/Mylers-Earless-Pressure-Radiator-2001-2018/dp/B078SK42QZ

