I suspect this is the reason that many sewers abandoned their Necchis, the American and Japanese models of the time could sew for months or even years without being oiled. Necchi has passed through several phases, but the machines made in Italy before the Age of Plastic are, in my opinion, the best-engineered and most well-built sewing machines ever made.
The models that fit in this category are the BF, BU, Mira, Nora, Lelia, Supernova, and Lycia. Some of my Necchi collection can be seen at. Beginning with the Lydia, Necchi began experimenting with plastic gears and camstacks that have disintegrated over time and need to be replaced. A replacement plastic Lydia camstack costs over $100 - about 4 times what the machine is worth on the open market.