Identifying Interior Door Manufacturer

My house was built around 1890. Nothing is square, plumb, or done in any of today's standard sizes. I have four bedrooms, and all of the doors are in sorry shape. They're painted stile-and-rail four-panel doors. Three of the four doors have cracked panels, and one also appears to have a cracked stile. (They've been like this since I bought the house). It appears that a previous owner tried to fill the cracks with wood filler, but it's an awful repair that really stands out. On top of it all, I'm sure that there must be lead paint in all the layers of paint on the doors, so any work I do will have to be conscious of that. I've seen estimates of several hundred dollars per door, just to professionally strip the doors, without even repairing the damage. I'm sure a craftsman could repair them, but I have no clue about cost. And I have neither the experience nor the equipment to handle fabricating new panels myself. I'm considering getting rid of all 4 doors and replacing them with modern four-panel doors. I would just replace the slabs, not use a prehung unit. Unfortunately, all the modern replacements I've found are 1 3/8" thick, and my doors are 1 1/8" thick. If I did replace them, I'm thinking I would have to enlarge the hinge mortises on the jamb for a bigger hinge, move the stops, and adjust the latch strikes. I think I could do that. My wife would prefer to keep the doors, since they're probably original to the house. (I know, happy wife, happy life). I also agree they're neat. But we're also budget-conscious. Our house is old, but not ornate. It's not historically preserved or anything like that. There's no reason we couldn't replace them. I'd love some opinions on whether it's reasonable to repair them or not, and if my plan for replacing the slabs sounds feasible. Or any other options that I hadn't considered. Thanks!

I installed a new exterior pre-hung door. It has gaps around it ranging from 1/4" to 1/8". I know they make expanding foam for this but have read that it can expand and distort the frame, making it unusable. What is preferred for insulating these small gaps?