The mechanical part is one thing, but one would have to be very highly skilled in marquetry to do that fine inlay. The wood construction is ornate doable not so difficult with head scratching. Probably one of those projects where you couldn't stay on it consistently, work on and off to do it or it would make you crazy. An indefinite time period would be required, and a client much less interested in the price than the aesthetic results. There obviously are/were people like that. They want to have it and the fee is no object. If I were to take on such a grand project now, I'd say completed before I die, and a stipend of two thousand dollars a month is required. All in all not a bad investment for the purchaser it seems, or for their heirs. Figure a piece like that one day selling at an auction sale starting bid at one million.