I'm a little confused. You say the previous OS was Mountain Lion, but Mountain Lion is the most recent there is.
Then you say you're unable to recover files from the Lion backup.
Please clarify exactly what you have, and what you're trying to do.
If you want to restore your entire OSX partition, including OSX, apps, user accounts, settings, and data, you can do that from any backup, but not via the Time Machine browser (the "Star Wars" display). Instead, you do a full system restore, per Time Machine - Frequently Asked Question #14.
Sorry for the confusion. A big mistake. I meant to say Snow Leopard, not Mountain Lion. In fact my "vintage" MacBook Pro is unable to use Mountain Lion.
Clarification; steps performed.
1- Prior to the Bootcamp partition I was running Lion. Here's where I used Time Machine to create a backup
2- In order to partition I had to move back to Snow Leopard (as per several calls working with an Apple tech)
3- After reading other people's experience with updating my system back to Lion with a Bootcamp partitioned (NTFS) I chose to keep the laptop configured with Snow Leopard
4- Attemting to use the Time Machine backup from step one, above, is where I face the problem. I can see the dates of the first Time Machine backups, but they are grayed out.
I hope this helps.
Reverting from Lion to Snow Leopard is a problem. Some apps, especially Apple apps such as Mail, aren't going to work with the Lion file/folder setup.
When you erase a disk, it's treated as a different one for some purposes, so most likely, that's why the earlier backups are grayed-out. You'll need the procedure in the green box of #E3 in Time Machine - Troubleshooting to see and restore from them.
You might also have a problem with permissions, if the user account you're now using isn't recognized as the one that was backed-up. You'll see the small red "no entry" icons. If so, try a different user account (create one if necessary).