Extracting Mail Archive From Time Machine....How?

So here's my problem.

I have a full backup of my MacBook pro on an external HDD using TM from 6 months ago.

2 months ago my MBP went doolally and I had to completely reinstall OSX. The thing was I was 4000 miles away from the HDD mentioned above at the time and couldn't restore from the TM backup. I had to do a fresh install.

The only thing I really need is my mail archive which was on the backup. Next week I'll be reacquainted which said HDD and want to extract either The Mail application or the Mail archive which was inside it.

[When I say archive I mean I'd manually made folders and dragged all my emails off the .mac server for 2005/06/07/08/09 etc.... Each folder has a years with of emails in it and was housed in the Mail application].

Q: If I plug the HDD in will my Mac even recognise it as a valid backup of THAT machine?

Q: Can I even extract the Mail application and if I do will my archive be there?

Q: What will happen to my current Mail application?

Q: Can I manually search for the archives in The backup version of Mail?

So many questions.

Please help.

Regards,

James.