I’ve had my LZ-7 since 2011 , it’s been back for a service and battery change in the past .. I’m expecting I’ll be sending it off again for that soon since it’s been since 2015 since the last one . Question , how the heck is that case back fitted ? There seems to be no obvious access point nor does it show any hint of being a screw down . It’s not that I want to open it , it’s just a question I have .. I own a Tissot Visodate that has an automatic movement , but also has a case back that must have a secret way to opening it also (servicing will be done by Tissot).