Thanks Supurburbon,
Grizzly will be my next step, but I am now going to respond to the wealth of information I got yesterday. Investigation of my 3 jaw today, found a chip in one pin socket, removed same. Light test revealed space between the chuck and backing plate. Something I don't understand yet is like a tunnel of light close to the taper then dark then a band of light near the perimeter of the chuck shoulder. After chip removal I could not get a 0.006 feeler gage between the chuck and the pin holder assembly. When grooves in pins are starting to disappear the cams cannot be tightened enough to hold chuck, one revolution of each pin inward (groove in pin almost out of sight) cams seems to hold chuck but the wrench just goes solid without any feeling of cam rubbing
I believe some progress was made today.
I mis-spoke yesterday when I said the back of the chuck was flat, that is true for the 4 jaw but the 3 jaw has a slight shoulder +/- 1/16.
Thanks to everyone on this problem.
It's off to Grizzly world so have a good day
Raay