Finding the manufacturer might be a bit tough but certainly would be the
best way to get replacement sashes.
Couple of things to check out:
1. Look closely at the hardware...Cranks or double hung window latches
might have a name on them.
2. Look for the tempered glass "bug". It will be in a corner of the window
usually near a corner. It's about 1 1/4" square and sometimes they
put the window manufacturer's name in it.
There were not as many makers of clad windows in the 90's as there are now.
Andersen was, and still is, one of the big dogs in the business.
I'm just The Door Guy....Maybe the window guy will have more ideas!