I guess it's partly true. Do you go by the black japanning alone? I have a beige 201K23, and I have seen a few in the black finish with simple gold decals. The later aluminium 201 version was only made in the Kilbowie factory in Scotland, and I think the last batch was late as 1962. The black cast iron versions were made a bit into the 1950s.
For the slant shank 301, I don't know when the production ended, but the 404 is a simple straight stitch machine, and all the 400s and 500 numbers are as fare as I know all metal machines. These are of course beige.
Singer 99 was kept up for a long time too, and came in the black shiny japanning up until 1958. It continued as the beige (or greene) 185 with slightly updated exterior, but remained much the same all metal model as the 99.
It's easy to over look, but model 66 was kept up for a long time too, and I don't think it ever came in any other color than the black japanning. I know the last 128Ks were made as late 1962 as well, and I think they all came in black.
The last 301s is said to have been made in 1957, but I don't know when ended the black finish.
Last edited by Mickey2; 03-27-2019 at 10:59 AM.