Looking to get started in racing

I'm considering getting on the track, having ridden on the street for fifteen years, and it looks like fun to me (I did some cornerwork at NHIS this summer). I came across a 1969 BSA B25 Starfire in fine shape and am wondering if this would be a good bike to start with. I'd like your advice about this bike or another older small displacement bike that would be a good choice. What work will I have to do to get it track-ready?

Thanks,

Brian