Hi, I've got 3 queries here.

First one is that I have a Jackson D2 Mark Morton signature model which has been signed by Mark Morton himself when I met him 2 years ago. I've been advised to get a value of this for insurance purposes. Does anyone have any idea how much this is worth?

Second query is that there is a lot of buzz on the a/d strings when played open. Any idea on how to fix this?

Lastly, is it also correct to tune up to the note and not down as I've noticed the g string slips a bit but is better when I tune up.

Thanks