OK Flip, thats close enough. 
The CURRENT A47 slip is actually behind the camera, this is the original one. If you go through Wansford northbound, at the far end of the village is the roundabout where you turn left or right onto the A47 and straight across for A1 N.
Well go straight over but note a small turn on your left called (wait for it…) Old North Road. Thats the old slip road out the village thats visible in the old pic and behind the hedge in the second