After making a few stainless blades in the US in 1962-63, most Personna DE production for the US market was done from Scotland in the UK until about 1967-68 or so....The stainless blades from that time are passable. Clearly you can shave with them.
Some have called them dull or worse for a stainless blade. I found them to be OK- or so.....
Were they using Wilkinson Equipment?
I have some of the Personna blades as pictured above. Mine are made in the USA. Exact same packaging including the nifty hinged case. The shaves are decent enough but not as good as later stainless steel blades from the late 60s to the 80s