This is another negative about McCall...one of the factors that's held him back...made a relative underachiever of him IMO. There's no reason why McCall shouldn't knock Primo's head right off his shoulders...why this is even a thread question and not a foregone conclusion were it not for his negatives.
Pardon, the environment McCall boxed in was no 185lb devision for blown up middle weights where you could oaf around the era with SIZE ALONE, brandish your arms randomly around relaying on your height. The environment McCall boxed in you needed some avarage punching power (+ aiming skills to apply it) to at least make McCall hide his face from your punches and the defensive abilites to protect your face from big heavyhanded 6'3" to 6'5" hitters with a raech 8 inches longer than little 6' Sharkey. Once more, a devision TWO WEIGHTCLASSES above yesteryesteryesterday.....MORE POWER, MORE CHIN, MORE RAECH, if not more skill arguably too! Carnera would at least got teached ALOT better footwork and defensive boxing and coordination to survive. He would definately not make it like he was and better stay in the circus, which would be more healthy.
If you look at his body of work and compare it to Primo's, I don't really see how you'd walk away thinking Primo was a sure fire winner. McCall is hardly just a fighter who won a single relevant fight his entire career... he was active and a contender well into his 40's.
You wouldn't walk away thinking that Primo was a sure fire winner, but it would be more than reasonable to make him the betting favorite!
I can imagine it being a toss up sort of fight, but I would have to lean towards McCall if I had to choose.