Please see attached

Hello! As long as the distance between the two installation hole centers are 3-15/16", then then my top recommendation is the 82-030 handle set. This has the same hole spacing and is traditionally used with  mortise locks like our  82-218, 82-265, and others.

I can't see your old mortise lock to confirm that our handle set is compatible with it, so if you have any doubts please feel free to upload a photo of it for me to review. Otherwise the 82-030 appears to be our best option for now.