I WAS GIVEN A PRE-PRODUCTION QUARTZ 600 MODEL TO TEST WHEN I WAS A SERVIS ENGINEER, THIS IS STILL GOING TODAY AND IN VERY GOOD WORKING ORDER, IT HAS BEEN MODIFIED TO KEEP IT UP TO DATE.
I ALSO HAD A PRE-PRODUCTION MULTI-VENT FOR TESTING TOO, WHICH IS ALSO STILL IN VERY GOOD WORKING ORDER.
WITH...