Last thought on the shot plot. I cleaned out some autumn olive, multiflora rose, and Virginia creeper last spring. Realized I missed a little walnut and some grape I need to clean out on next visit.
I've not read through this whole thread, so this may have already come up, but.... Nick Botner was mentioned early on... Temperate Orchard Conservancy had Botner's permission to clone his orchard, and they've been working, for several years, on getting them all cloned. You can order scionwood from them... though I've not looked at the offerings.