Following Brian's comment I started chasing the play. I changed the kingpin bushes and thrust bearings, then the axle pin and bush, and finally the wheel bearings. The front end is now as tight as new. Rather shows up the play in the steering box! Are shims available anywhere for doing the adjustments?
Yep,although some very handy member proposed the idea (and maybe put it to use as well) to make a shim which would fit on top of the top bearing in the steering box,thus tightening it up.
The topic should be somewhere in the old forum i guess.