J Guy - got the trial GetDataBack - and tried it - using Lenovo backup machine.
First observation was it was slow - really slow. It came up with a boatload of errors but could have been because I had made a small FAT partition on this one HDD. That aside - it looked like it was gonna take a whole 24 hours to get anywhere and as storms are coming in I may need to shut down over night - for safety.
BTW - I stopped process soon afer sector 1,000,000 - and total was in excess of 350,000,000 - so long time needed - probably treating drive as one partition - instead of the three or four it should show..
I am thinking more and more this could be a lost cause, tho not given up entirely.
Before my old machine was abandoned I was getting extreme and seemingly unstoppable HDD activity which was compromizing CPU - sucking up all resources nearly. Despite a virus scan coming up negative, it had seemed there was some process (I could not identify) that was screwing things up. One system restore seemed to help for an hour or so then it was back to trouble.
Whether HDD controller had gone crazy I am not sure but anyways - it was taking for ever to acomplish even smallest task. Same in safe mode too. That PC had had well over 3 years hard work.
Thx again for your suggestion.