Just achieved a bit of a breakthrough. After dragging 2 missing files into the MB inbox and then adding to the library, I tried dragging the entire MP3 music library folder into MB inbox. Then selected all and added to library, then ran manage duplicates. Now have only 13 missing!
I do take my laptop overseas once a year for a few months so it would be good to have MB standalone on that.
Also I have all my music on a NAS drive connected to a media center inside the house, so as I don't have to have my main PC in the office, which is detached from the house and has the modem/router connected to it, running when I want to listen to it.
How I work all this, is that I add and organise all music through my main office computer, (easiest and fastest and I don't disturb anyone) then I synch it when I've made enough changes, to the laptop and media center.
I also have another PC in my office that I just use for downloading, burning, video editing etc, and connected to an amp and speakers for a bit of volume when I need it in the office or outside, it also has a turntable attached. That accessed the windows media player library through the network.
So you can see I've made it hard for myself by deciding to ditch MS MP and go for MB.
I think I'll persevere with individual installations on each PC and go with the synch program. It'll probably take a while, but should get easier with each one.
I really appreciate everyone's comments and suggestions, you've definitely helped. I'll keep posting as I go along if that's not a problem in the forum, hopefully it might help someone else out there trying the same thing.