Door handle and lock for Mayfair sliding door installed in the late 1970's

Thanks for your post! The door handle you have looks like it can be replaced with the 82-003 Sliding Door Handle Set. You'll need to compare the dimensions below to confirm that the installation hole placement is a match.

If you'd like to convert this does to one that uses a key lock, you'll need the 82-306 Keyed Exterior Sliding Door Pull.

Alternate image for 82-003

View of latch