Awesome table!! A few thoughts:
1. I think that table is probably no newer than about 1974. If you look at the lower half on the end you will see a serial number. If you post that I can give you an idea of the manufacturing date, but I'm guessing it's >40 years old! I predict a serial number around 23,000.
2. That thing is an amazing condition, given it's age. I think you saw my 1972 table's condition on the other thread.
http://foosball.com/forum/index.php?topic=5058.0Yours is like new by comparison.
3. Big yes to getting feet levelers and shaved feet. Makes the table much easier to set up and play on.
4. Re: point 3, the person you want to talk to is Alan Cribbs at Bonziniusa.com He has the leveling feet for sale and can grind the player's feet. He's also just a great resource for all things Bonzini. Excellent prices for parts, super fast shipping, great customer service (will order special parts from France, etc.)
I have a Tornado coin-op and a Bonzini B60. Both are great tables but I'd say the Bonzini gets played 80% of the time. It's just a really fun table. How much is it worth? That's a tough one. If the condition is as good as it looks I'd guess between $1,000-$1,500. But I say keep it!