I'm not sure if the 45mm UPO will be the same as the 42mm PO but the 42mm requires the tube to be epoxied as the tube is slightly smaller than the threaded hole in the case. A quick fix I tried and had success with (while waiting for the gen crown/tube from ofrei to arrive) was to pull the crown and stem and gently squezze the tube making it a bit out round....giving the crown something to screw into. It worked for me and allowed me to continue wearing it until the replacement parts arrived.