Sadly, there doesn't appear to be definitive biography/discography for Roy Smith although there is a fair bit of information about Roy scattered over the web.
Here's some very rare, but unfortunately low fi, footage of Roy performing live -
The fellow who posted it on youtube, Richard Hooper, played drums with Roy for a period, in the late 70's I believe. I had some contact with Richard and I'm sure he would be happy to talk about his experience of working with Roy to anyone who is interested..
I was also contacted by his daughter, Sabrina Jeffs, via youtube and here too I'm sure she wouldn't mind anyone getting in touch regarding her late father. She mentioned she was going to post some of Roy's music but hasn't as of yet. I'm guessing there's a lot of unreleased material somewhere, either rough demo tapes or whatever, as Roy apparently re-recorded his songs several times and Richard was telling me he'd play stuff on tape in his car.
Roy was undoubtedly a great talent, both as an artist in his own right and also as a songwriter and producer.
Yet another who's flame burnt bright for a while before his untimely demise.