AHA! Yes PG502 is a fine unit, the back term 50 Ohm is handy. I have several, neither has ever has any problem.
For scope cal, the really fast rise pulses are from PG506 and Leo Bodnar's 40 pS pulser
As a general use PG with fast capability PG502 is best.
The resistors you highlight are not critical to the performance and even a 5% value should not affect it.
I dont recommend Removing, testing and replacing the parts if its performing satisfactorily.