The main fact to find out is whether the optical design of the 7 inch you have found is a Petzval doublet or a Zeiss triplet(telephoto) . The original Zeiss triplet on the Mond was a triplet of f/7. Cooke mounted the Zeiss lenses onto the Mond astrograph for Robert Mond.I would look for some markings on the lens cell/housing which may show it to be a Zeiss.
Denis