Speaking has an old(er) man with 20+yrs of weight lifting, the latter half of that with a professional trainer, I can say with all certainty, take it easy. You have injuries, everyone does, the older you get the longer they take to heal. Some injuries, like two of mine, are life altering and can hinder your ability to ever lift hard again. So listen to your doctor and your body. If I had listened sooner, I would not be in the painful position I am in today.
A hard lift is hard on the body, 2x when you are older, and I am guessing from the 15yr break, you are not a spring chicken anymore.
There are lots of ways to get into great shape that are less stressful than heavy/hard weightlifting.
Climbing machine, elliptical and swimming with very moderate lifting and a great diet will do you more good than risking a bad injury.