All the 66's have horizontal bobbins that can be accessed from the bed of the machine. They had several different decal sets used on them, and also plain black in the 1940s. Don't know if they ever had the crinkle finish...I don't remember seeing one, but I'm probably wrong. They started very early in the 20th century - my 66-1 is from 1909. Minor changes were made to some of the component parts early on, so they are not all interchangeable on all models of 66s.