One brass nut?

[Schiada]

Have a KG7H that I got in a box. Been cleaning parts and have one brass nut 1/4-28. What do you think it was for? Here is the photo.
49984

[zul8tr]

There are several locations where NF (National Fine) threads are employed, like carb studs, power head studs to exhaust tower. As for the single brass NF nut? Maybe it is a stray? Maybe those familiar with the KG series will chime in.