Technically, there are (or were back then) two variants: Production Car Trials and Classic Reliability Trials. They seemed to operate much the same, except one required standard road tyres and on the other you were allowed "knobblies".
I can't actually remember which was which, but look at my Sunbeam Sport in pics (3) and (4) and you'll see they are one of each.
I've put each picture on a seperate page so you can view them at your own pace; the .jpgs are a bit large (about 80k) since the photos are old and crummy so I went for a slightly higher quality compression to try to keep the detail reasonable. Still, they should load in well under a minute each.
