I spend a fair amount of net time probing around for more data on the Series 60 with no positive results. There are two people at Prevost that may be able to help you. One is Bill Jensen and the other is Randy Costello. Last I knew Randy was in Nashville and Bill has been floating around, but you could track him down from the main PCC 800 phone number in Quebec.
I was going to write something here in French, but I get criticized for doing that.