A local locksmith would be where I would start.

Did some previous owner gut the lock? That would be a shame. Those old locks were built like tanks.

I Googled on antique door locks and got lots of hits.

A Modest Example

What I have done is cut a piece of pine / plywood to the width of the lock - glue it in mortise, cut off flush with the edge of the door. When dry - bore a hole for a latch. Several inches above the latch install a 1" deadbolt.

My need is someone to remake the insides of this lock

That's not going to happen. You could buy a new mortise lock.

"My need is someone to remake the insides of this lock." Check the search results purveyors and see if you can find a lock with the identical dimensions and cannibalize the new lock for parts.

You need this guy, Rick's Restorations from American Restorations or someone like him.

Try these guys. If they cannot help you they should b able to send you in the right direction.

It's not "rabbid" it's a rabbeted lock.

Geoffrey, a regular mortise lock will not fit a rabbeted door. That's why these oddly-edged locks were made.

I replacing it, make sure you get the correct "hand" because they come left and right.

I found one on ebay:

https://www.ebay.com/itm/Antique-Eastlake-Entry-Door-Lock-By-R-E-Co-Late-1800s-7-7-16-x-1-1-4/111537870793?hash=item19f82cd7c9:g:BAAAAOSwaNBUf1kr

Casey,rabbid is how I feel dong most door repairs. By looking at the number of tools laying round when finished with a door,I would need three boxcars full of tools to build a house.