Sounds like an E-type from your description. We can't see pics from your email account.
Jenson has LX for $10. Free shipping if you buy $40 more worth of crap. Top pull if your derailer cable goes along the top tube, bottom pull if it goes along the down tube.
http://www.jensonusa.com/store/produ...erailleur.aspx
Here's a pic of one. Ring goes around BB driveside cup. Two bolts are where the derailer attaches.
Shimano LX E-type Front Derailleur - M570 - SOLD by
Tuftronic10000, on Flickr