Talking about 3D printed nuts and bolts, you can cut the middle man and buy a 3D printer, then print yourself as many pieces as you want. 
 
	I found this designer on Cults3D that modelled many kinds of nuts and bolts in 1/12 and 1/24 scale.
 
	https://cults3d.com/en/users/gScale/3d-models
 
	Pierre T.