It is pretty unusual for a Kenmore model to span model years. Only thing I can figure is that after 1971, the model 1516 was no longer manufactured. A few years later, Kenmore must have figured they had a winner and "reintroduced" it in 1977. I don't know the true answer, but I actually think…
Kenmore Vintage Original Collectible Sewing Machines for sale
Vintage 1977 Kenmore Model 158.15160 Sewing Machine Documented
61 Kenmore Sewing Machines ideas
Restoration of a 1970/71 (or is it a 1977) Vintage Kenmore Model
Vintage Kenmore Sewing Machine
Kenmore Brown Collectible Sewing Machines for sale
Restoration of a Vintage 1941 Singer Model 201-2… Meet Lola
61 Kenmore Sewing Machines ideas
Restoration of a Vintage 1973 Kenmore Model 158.18032 Sewing
Kenmore Sewing Machines for sale