Ha! An amazing thing happened!
I was going out to a friend's house last night to do some singing & wanted desperately to record it, so I thought I'd try the ratty old mono cheapy mic I had for my PC when that was alive. That worked OK but not great & meant I had to record in mono mode.
On Sat my brother-in-law had been round to borrow some PC game CDs & we had emptied out the drawer onto the table. So there on the table still was this tiny little mic that had come with a modem years ago. I had tried it in a tape recorder before but it had been shite. However - I thought I'd plug it in just to see ..... and lo & behold it were briliant!!!! It is stereo & must be one of these plug-in-power jobbies because it worked really well on the minidisc whereas it hadn't on the tape machine.
So I had one all along & just didn't know it!
So - sorry to have bothered everyone & thanks for all the help.

Kris