Cheers for that John,
I've got a GPUSB which has yet to be used. I might give that a whirl first via a webcam and PHD on a laptop. Keep it simple to start with and avoid all the EQMOD blah blah options which seem to confuse the issue. If that is too hard then the Autoguider might be the next step.
Really need to build the Observatory first to get round this put up, tear down situation for every session.