Before you spend more dough, try to find out why you can't adjust out the play. One common problem with bikes of that era is bellmouthing of the lower head tube, so that the lower head cup develops play in the tube. All the adjustment in the world, can't solve that.
If it is a headset wear problem, you might be able to source a set of the bearings and races for the headset for less than a new headset.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.