3 Game Used bat questions. Please help

[Buster23!]

Here are my three questions.

Whats are the characteristics of a Matt Willams GU bat?

Whats are the characteristics of a Will Clark GU bat?

Whats year did they start to use pine Tar? I see a ton of game used bats from the 70's & 80's and they never have pine tar on them. Thanks guys