I agree with Joe & Leon. Frequently, just oil and patience will go a long way to getting the machine going again.
I'm fairly certain that that is not an aftermarket.stitch regulator. I was under the impression that SV machines were for a specific task and consequently the parts to make that task easier. It could be the decals or for a specific destination.
I believe that the 15-96 is closer to the machine and parts that you have. The manual can be found at
https://www.sil.si.edu/DigitalCollec...2666/index.htm and a pdf format can be gotten at
https://archive.org/details/singer15961598manual There is also a parts list that can be found at
https://www.supsew.com/download/Sing...-97,%20-98.pdf
There are descriptions of the various domestic 15 class machines at
http://needlebar.org/main/15chart/index.html I do take exception to those made at Kilbowie being the same as those made in US with the dash being replaced by a "K." That is probably true of a lot of them, but I know the 15K30 and the 15-30 are different machines, with the 15K30 being a wheel feed. There is also a model list that includes 15's at
http://www.ismacs.net/singer_sewing_...sses-1-99.html
Janey - Neat people never make the exciting discoveries I do.
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