Normal spring sound ?

It has been over 7 years since this old Slavia 631 Lux was last used. I would like to refurbish it, but the spring has a good sound, and I wouldn’t want to replace it. Currently, there is a 7.5-joule limit on springs, but this model predates the restriction and has a power of around 12-13 joules. When these rifles were manufactured in Czechoslovakia, they were not yet subject to such limitations, which is why I want to preserve the factory spring. I don’t want the original spring to break. Thanks !