A 73-year-old woman and a 69-year-old man, both having experienced separation through divorce in their past, serendipitously cross paths and find solace in each other's company, yearning for a companion.

For starters I'd get rid of the specific ages of your characters and just call them an older couple, or later in life, in their twilight years etc.

You need to include an impediment, or what's at stake.
Your current logline already has a conclusion imho.

Suggest something like:

A chance meeting for a man and a woman later in life after both have experienced love, loss and separation could prove to be enduring, but both are wary to put their hearts on the line again.

A serendipitous meeting between a man and woman in their twilight years could mean a last chance at love if only they can find the courage to put their hearts on the line one last time.

Oh, I really like Libby's last one. Made me want to read the script if it reflects what the script is about. Great job, Libby.

One other thing - if it's a comedy you better hint on it in the logline too. Otherwise it reads as a dramedy which is totally fine.