No, that is not a 15 clone, nor even a 15 class machine. It is a New Home model AC probably mid to late 1930s. Great that you have a manual.
It takes a special needle that is not often seen for sale. It is called a "CC 1221" and there is not a modern equivalent. There was someone who tells of grinding a 15x1 needle to work for the needle that this machine takes at
http://myperfectstitch.blogspot.com/...r-classic.html
While the bobbin and bobbin case are similar to White machines, they are different. It
looks like you got at least two bobbins.
I'm not sure what the screw is for that is underneath the hand wheel, but it is not a "motor boss" and I can't tell if it is centered so that one could just add a hand crank on and sew also the screw threads might be different. The spokes on that hand wheel are spaced further apart than the Singer machines. I'm wondering if the smell was rubber or dirt or electrical. I'm not really into electrical stuff, either. I have heard that some motors do smell or smoke a bit after sitting for a while. It could just be dirty. I am fairly certain that the knee controller could be removed and a foot controller could be put on. It seems like I have seen some controllers that were initially had the knee lever but it was removed to use as a foot controller. It may be awkward but you could twist it to the back and still use it as foot control. I know that Mariam used a steering knob on one of her machines.
I'm curious as to know if there are some red lettering on the bottom of the attachment box. With the pattern of the box, it may be hard to see.
Also something to note would be that the hand wheel turns opposite of Singer machines. So it rotates clockwise as you are looking at the hand wheel.
Janey - Neat people never make the exciting discoveries I do.
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