I need small parts cleaning brush with the bristles pointing straight out parallel with the handle. Like the one in the picture that I made. I have several large part cleaning brushes but I need small one to clean inside things like distributor housings and carbs.

I have taken small paint brushes and cut the bristles off. If you cut them to 1/2" long
they are pretty stiff

How close are you to a Harbor Freight? You might alter one of these offset wire brushes like you did with the tooth brush.

https://www.harborfreight.com/6-pc-detail-brush-set-69526.html

Here is another one "steel".
https://www.harborfreight.com/steel-detail-brush-69525.html

Pricey
https://www.mcmaster.com/wire-brushes

Dan, How about the small acid brushes (with the metal handle) used to apply flux while soldering?

They are available at most hardware stores, plumbing supplies, and Home Depot & Lowes, etc.

Good thinking Bruce. Tried one and the bristles are not strong/stiff enough. I even tried to trim them down to about a 1/2" length and still not quite good enough.