I have done it, but I have access to various leathers and an industrial sewing machine, this is in reference to recovering leather or nylon covered plastic saddles, some with padding some without. graphics are a separate issue.

Note "gel" padded saddles are another issue, tried one once, and the "gel" had morphed into a scary gel and oily goo... weird science, that one I trashed instead of investing more time. There is more than one kind of "gel" so your situation may vary.

Having access to various adhesives helps, no one type fits all.