LVS vault model bat not matching the game issued model?

Greetings everyone. Tried to post this a few days ago, but I don’t think it ever was visible on the forum. My Apology if this is a duplicate post.

Can anyone tell me why a Louisville Slugger “vault” bat would have a notable difference compared to the same model of a game used / issued bat? The reason I ask is I purchased a vault bat with the model number A80 stamped into the knob and also stamped into the end of the barrel. It is my understanding that the stamping appears at the end of the barrel after it is approved by the player to become a new model for him. There is no center brand logo or other markings burned into the bat. There is very faint writing in a red pen or red marker that is faded. I think I can make out the word “model” written on the barrel, but nothing else. After doing research, I found Vince Malta’s Louisville slugger bat model book state that Luke Appling in 1952 had a new model created for him, which was designated model A80 in 1952. Cool! Yet, my confusion is due to the following. Zanes Bats is selling a model A80 Luke Appling bat on eBay, but that A80 has the knobless style (like a U1). My A80 has a Ruth knob style, which is very confusing to me. Has anyone seen a vault bat prototype differ from the actual model design like I have described? Very curious and would love to be educated on the topic.

Thank you!

Giving this a bump because I know we have some bat experts on the forum... would appreciate any insight if you have some. Thank you!