I think the inner is actually hard to find unless someone has started producing it again. It’s different than a Milano, which is still available. When I needed one I found it at Alfa Parts in Berkeley (aka Jon Norman).
Current: 85 GTV6, 69 Duetto, 17 Giulia, 74 GTV
Past: 65 Giulia Sprint GT, 77 Alfetta, 79 Alfetta, 87 Milano Gold, 74 GTV (Euro)