Again, these are possibilities, no one will ever know what was installed but thanks for the possibilities. IMO, I think the 6500 or the 5721b may be the best possibilities.
For the record, the pulls were Edwards 270-spo pull stations with Edwards 439d-6awc bells which are tied to the current QuickStart system whenever an alarm goes off. Also, I did stand next to one when the system went into alarm and it was VERY LOUD!