Nice bikes. Here's my '95 AL550. Picked it up at yard sale last summer. It was in pieces, had a mis-mash of parts and an extra set of wheels. A little bit of work and some new brake levers and shifters and It's a pretty fine MTB.
If I remember right all the ALs used the same frame and the model number (150 - 750) was determined by what compents they were built up with.
Here's a thread with a '95 catalog scan and some discussion:
http://forums.mtbr.com/vintage-retro...ns-339251.html