New lock

Thanks for posting! The mortise lock you've chosen, part 82-265, does appear to be the correct replacement. However, you'll need to compare the dimensions from our diagram to confirm. 

Your handle set looks a lot like our 82-086 Legacy Keyed Handle set, which is compatible with the 82-265.

Carefully review the dimensions below and compare them to your existing mortise lock and handle set to confirm that these are the correct replacements.

Alternate image for 82-265

Dimensions for 82-086

That should not effect the function of the hardware. It will work fine, so long as the placement of the installation holes and the position of the thumb latch lever match up.