I did plenty of cross racers as a schoolboy back then when Kieth Mernickle was winning the senior event.
http://www.veloveritas.co.uk/2012/12/09/keith-mernickle/
http://www.veloveritas.co.uk/2012/12/09/keith-mernickle/
Here's the link to the one I picked up. Fairly rough and I'm not sure those tyres will be any good. It's in the to do pile so may be a long time in getting back on the road.
http://pages.ebay.com/link/?nav=item.view&alt=web&id=122046782547&globalID=EBAY-GB