Currently offered for sale in the UK is this photo card. The description indicates all signatures are by Paul. Might be secretarial? Any other thoughts?
I checked myself again, and I was wrong. Here is a full set in the hands of Paul and it's similar to the set in the original post, so yes, they are all by Paul. When I looked at Paul's autograph in the the original post for the first time, something looked strange to me, but I guess it was only in my head :-)