Leave them as they are then. If you do fit new faces, which I know some members have done but Peter Horton does it much better, then the clocks will look brand new, which you don't want. Peter will also service clocks without changing the look of them but you say yours work fine, so you don't need that either.
The bike is nearly 50 years old, unless you change every single part to OEM NOS original parts, which is impossible, and financial suicide, there will always be parts that show their age and I think thats lovely. Even on full top notch restorations we always leave a few parts that are totally 100% original from the day that bike left the factory.
If its a daily rider, it's soon going to get battle scars and war wounds, if its a show pony trailer queen, then that is a totally different thing.