If you have dismantled or deconstructed your Nardi wood wheel, sad to say that the cost of reconstruction may exceed the cost of simply finding a suitable replacement. I don't know enough about the construction of Nardi wheels but it sounds to me like a fairly custom process to machine new wood to the right specifications, assemble it and refinish it.
Madera does exceedingly beautiful work, and that precision and flawless finish comes at a price. When I was having some work done on my car from 2020-2021, refinishing all my interior wood was on the list. The cost of refinishing by Madera (I sent the wood out to them for examination and quotation) was about the same as replacing with new (albeit reproduction) wood offered by Authentic Classics. So I opted for new from Authentic, and sold all my used wood to help defray the cost.
If you do an online search for "wood steering wheel restoration" you'll come up with a few firms in the USA that do this work. However, most of them seem to be in the "restoration" rather than "rebuilding" which means the wood itself must be salvageable. It surely doesn't hurt to contact these firms and pose the question.
A quick check on eBay reveals plenty of Nardi wheels for sale, in several models and colors, priced between $250 and $500.
