I got this piece of live edge Ash from ArborScape Wood Products. I planed it down, stripped the bark off the edges, and then sanded it down well. I then finished it with Osmo PolyOil. The finish looks great.
I bought the antique Singer treadle sewing machine from a local fella and then attached it to the bottom of the piece of wood using a socket head set screw. I was concerned that using a regular screw would pull out too easily with use, especially when moving since the base is pretty heavy.