I would suggest you get in contact with FinsRin/Bill P and ask him about spare B-58 engines. He has a couple of the Italeri kits plus some box scale kits from which he might be able to source your parts. No promises but that is the best I can do is steer you towards a possible source. I gave away the spare engines I had saved from the one Italeri B-58 kit that I had years ago.