Cole Sewell Estate Series ES0110446
I'm sorry to say that Cole Sewell has been out of business for quite a few years now, so you aren't going to find an exact match for your handle set on the market. I also wasn't able to cross reference that code in my records, so at this stage I'm not sure what you have.
I'd be happy to offer a few suggestions from our inventory, but I'll need photos of the original handle set first. Written dimensions would also help me narrow down the list of possible contenders.
In my experience, Cole Sewell doors aren't that difficult to repair with modern hardware, but some handiwork is always required. Drilling new holes is usually the minimum of what you have to do, though depending on how different the new hardware is compared to the original then the project may be more involved. Either way, that's something you should brace yourself for. You're not going to find anything that will fit on the door as-is, unfortunately.
Thanks for these photos, this is a huge help. I see what you mean about the handle not reaching the keeper. That's a pretty large gap; you may still be able to use this handle set, but you're going to have to adjust its position on the door to be closer to the jamb. At the same time, you're also going to need a new keeper that can reach out further to interact with it. The goal is to have them meet in the middle.
Odds are you won't find a keeper that will meet the handle perfectly; if that's the situation then you can use washers to pack the keeper out. That will let it stick out a little further.
Drilling holes is going to be necessary, unfortunately. As mentioned before, Cole Sewell has been out of business for a long time, so you aren't going to find anything that fits perfectly. There's also no such thing as a truly universal part in this industry; I wish, it would definitely make my job a lot easier. Unfortunately every handle set you'll see, even the general-use ones, are made for specific applications. What you're doing here is using an off-brand part in a unique application, so alterations will be necessary. There's no way around that.
Sounds like a plan. Best of luck with the rest of the project and please let me know if you had any other questions. We're happy to help as best as we can.