This was his other signature card and he does have a large auto.......which may have played into the fact him signing on smaller stickers may not have been something he was used to doing (squeezing his auto into a smaller area).
I have no queries at all that the above sigs of B.Mccullum are authentic. And I’ll agree he does have a very free flowing sig but the Topps sigs are not even close I think saying because he had to sign them smaller would be clutching at straws. Have a look on you tube at the doco in Feb about Topps faking autos round about same time this set being produced. I believe this set is a feeler set to test the market no real strength to it.