Excellent it is working. The onvif url is http://192.168.1.138:8080/onvif/devices
I assume /devices and /device_service is the same. This works with three different szsinocam cameras so would probably work for them all.
I loaded up the 32bit software on an oldl windows 10 tablet and it picked up the cameras straight away with no help from me. The 64bit desktop needed the custom URL.
Many thanks