Will either of these help?

http://www.sewconsult.com/kenmore/15...manuals_3.html

http://www.mastersewusa.com/masmag_free_manuals.html

Scroll down to Sears-Kenmore and click on Model 15

try Hammerwall.com they have alot of manuals for alot of things.

I get lucky on Etsy now and then - found a manual there for my Kenmore 158-1651.

A lot of the Kenmore 158's are really really similar, so there's a good chance a manual from another model would work. I see a manual for a 1750 on Etsy that might work for you.