You are fortunate to have a Model 9 with such a great story behind it.
The Walther Model 9 is a splendidly machined and finished little gun. I have one that is well worn (it must have been carried for many years, as nearly all the original finish is gone), but it is mechanically perfect and has never malfunctioned in any way. It feeds .25 FMJ with monotonous reliability.
That a gun so small can work so well is amazing. Nothing not to love about pre-war Walther craftsmanship.