I've noticed (from your discussions) that apparently some varieties of bourbons are brewed in more than one location? and also in different lots?

When I am shopping are there things that I'm looking for that indicate a better chance of a better bottle of bourbon? Or influence the value in terms of collectability or novelty? I'm not a collector, generally a drinker, but it is fun to have things that are a rare find!

Lastly, i recently bought a ORVW 15, the serial # is A9667, does this mean it is from lot A and that this is the 9667th bottle from that lot? Is there a way to know how many were in the lot?