Still no luck..
HDToolbox finds the drive and can identify it and read all the info from it no problems, still cant get it to appear in Workbench. It had an 850Mb drive in it that I 'borrowed' from an old laptop, but I needed to put it back, and that drive had WB installed on it no problems. However, when I set up that one I didn't use HDToolbox, I used another utility, and I can't remember what it was called.