From the pics I took I believe the replacement I need is a mortise and tenon unit. measurements of it are: length of handle part is 9.5 in., length of unit in door jam is 4 & 1/8in., corresponding part in the lock part of the handle is 5 & 5/8in.
I'm a widow and can repair lots of things but not this! A good handyman friend will do it. Thank you Karen.