Based on the scales, alone, I prefer the white pine because they look fresh and modern. The blade you choose could completely change my preference, though.
I voted both..from the side I like the look of the white pine slightly better, but viewed from the end with the contrasting spacer I think I like the walnut better. I think you did a really nice job shaping them and thinning them out on both sets.
And +1 on making a wedge instead of a spacer. I was resistant to this thinking a wedge was going to be a lot more complicated, my spacers were working, etc etc, until I made a couple sets with wedges. Very simple to do and really improves the appearance and how the blade fits in the scales.
I voted "I like both" in the poll, but I must say that the lighter pine is a much more unique choice; darker wood scales are much more common historically, and the light pine against the steel blade I think would read very nicely. I'm changing my vote.
Love the walnut for two main reasons. Dark is richer to my eye and flatters a vintage blade. Walnut (believe me) is a much harder wood than pine and will stand the test of time.