First time seeing an original A 5 pin center chute. Truly amazing it's still around. I've done service work for countless centers with machines as old or older than yours and I've never come across one. All have been replaced with the newer 6 bolt style/matching spider ring assemblies.
You're correct ! Put any 65 year old parts up against new parts, I'll bet I know which ones will still be here in another 65 years if given the chance.