Question on 41 Playball Copyright Variation

[Kutcher55]

Hoping someone can educate me or direct me to a prior thread that covered this topic. I was just made aware of a variation in the '41 Playball set. To be clear, I'm not talking about the paper version -- that is a separate topic. Instead I'm curious about the difference between the cards that have just the "C" (copyright) symbol on the back lower left corner as opposed to the cards that have the "C - 1941" symbol. I checked my set and 25 of my 71 cards (I'm one card short) have the '1941', all of them within the early (#1-48) part of the set so I suspect the variation was not extended to cards 49-72 but I would like to confirm this. Additional questions.

1. Is one version rarer than the other?

2. Are there differences in the card stock and/or size of the cards? When I did an informal survey of my own set it appears as though the ones with just the 'C' have slightly larger dimensions and aren't quite as bone-white as the ones that include 1941. This might just be coincidental because I only looked at a handful of cards.

3. Is there any value difference between the two versions, particularly on the key cards?

Any other info the experts might be able to share is greatly appreciated!