A skilled carpenter should have the skill set to do it but not without money. You might see if there are any millwork factories near you that could fabricate the door jamb with your specifications.

As shead states, a good carpenter or even better look for a local woodworking shop that advertises custom trim, beams, doors, etc. For a guy with the right shop it will be a piece of cake, but it will not be inexpensive.

but they are gorgeous and it will be worth it. :-)

From what I see, a similar pre-hung door is about 4k. Ballpark, what would the millwork cost?

YOU need to contact a millwork company and ask them. That's not something we could answer. I'd say a minimum of $500 but that's nothing more than a wild a$$ guess.

"From what I see, a similar pre-hung door is about 4k. Ballpark, what would the millwork cost?"

4K is not even close for a quality door unit, without the radius top. That frame will cost you probably $1500 to $2,000 depending on where you live and the wood type used

Will the local authorities permit you to use a reclaimed door? I would want to ask that question as the energy codes which control the specs for windows likely apply to doors as well. You also need to ask about replacing the glass with tempered glass as required for doors

I'd bet that has tempered glass as it does not look that old of a door. Good weatherstrip on both door & frame as well as a custom arch top storm door wood be needed for modern code compliance more than likely. So add that in.

When considering cost, don't forget to add the cost of the curved treatment above the door on the exterior and the curved mouldings that will be required to case it on the interior.