Hi Mark,
Now the guy to answer any vintage Wilkinson blade questions would be Not The Stig. Yes, he's soon to be the resident expert here at TSR. Hehehe, it's his own particular (peculiar?) very own monkey! I have no clue how he mighta picked that one up.
I'm familiar with those old blades and they're good. Used em myself in the past, when I tried a few old Wilkinsons. They weren't my personal favorite, but that should mean exactly nothing as to how they'll work for you. I know a bunch of people really enjoy those. Now that I think of it, I may have a few other different vintage ones in my rotation.
I'll be curious how they compare to the currently made ones,
Martin