Replacement Door handle with lock.
Hello,
We offer the 82-030B keyed handle set with 3-15/16" hole spacing, which I suspect would work for you but you would need to confirm that the latch on the inside handle is offset rather than centered. Take a look at the specifications below and let us know if you have any other questions. Thank you!
Thanks for getting back to us. It's tough to tell if the thumb latch is offset or centered since your photos primarily show the mortise lock. The thumb latch mounts on the inside handle, so we would need to see a straight-on photo of that handle to confirm, although it does appear to be offset based on what is visible in your third photo.
I'm also a bit thrown off by your mortise lock since it doesn't appear to be held in place by any screws. I would recommend having someone hold it in place when removing the handle set to prevent it from falling inside the door frame.