Add corrections for full manual lenses not identified in metadata

Would be great to be able to add lens corrections for older lenses that are not automatically identified. I have an old Nikon 50mm f/2 lens that has a design basically the same as the 50mm f/1.8. The f/1.8 correctly identifies, but the f/2 only gives me an option for a Zeiss lens. Would be great to be able to select from a lens in the database, especially when the lenses are identical in optical design.