Although spray painting with guns similar to what we use today can be traced back to the late 1800's, canned spray paint does not get invented until 1949. So although brand new pumps in the 1920's-30's were very possibly spray painted at the factory, would it not be fair to say that any station owned pumps that went through a repaint were likely done with a brush?
Just curious guys thoughts.

If a pump was re-painted by a station owner in the 1920-30's it was likely done with a bucket of paint and horse hair paint brush.
Many times they did not bother to remove the glass advertising globes. Evidence of paint over-brush on many glass globe bases.

I pulled the glass out icbtbe pump when took my parts to get sand blasted. There is not a bit of paint anywhere on the metal. But is orange paint on the glass

My first job was pumping gas at a chevron station and every year i painted the pumps with a brush out of a can of paint the Chevron guy gave us !!! I'm 77 years old !!! After i got older i started collecting gas and oil stuff !! Still have my share but am selling off most as my lungs have gone caused by COPD !!!

i have a GB 176 that I'm planning to do in Sunoco and put out in the yard. According to Jack Sims, the pump was made between June of 1931 and December of 1938. I have no intention of making a piece of jewelry. I just want to get the lighting working and make it look like it would have in say, 1939 if still in use and was repainted.
It has this crazy cracked up patina so I'm not sure what to expect, but I think I'm going to brush paint it. It is very likely that's how it would have been done back in the day.
I also have a crusty reproduction globe frame I've been rusting up for a couple years and set of repop lenses.

Sure many knows better than I but think anyting you do is not going to last if you don't bead blast it.They make some pretty good apoxy two part paint today. Back in the day I would say they used oil base enamel.

Steve, if your plan is for an outside presentation I recommend rustolium thinned a little. I have used it a lot to preserve that wonderful crackle on the skins and actually firms and protects it. By thinning it, it’s not as shinny plus it’s strong as hell for the outside environment. I just use a chip brush and work the paint in. Have fun.

Great idea with the thinning of the point Les!! Thanks!!! I'm going to try that in an attempt to keep that crackled look. If doesn't work, I'll the have panels blasted clean.

I like that pump the way it is. 80-100 years of patina. Throw a decal on it the way it is and light it up.

However, if you do try the thinned blue paint right over the cracked paint, you may want to use flat paint and maybe use a slightly lighter shade of blue, to make it look faded and aged, if your going for the rustoration look.

I don't hate the look either Steve. The pump looks to have been originally red but someone painted it white at some points in it's life. There is also this vague look of a mobil shield decal on it.
But I want to turn it Sunoco or some crazy reason.

Whatever you do to it, keep in mind that it will continue to weather once you put it outdoors. It looks like it has a fair amount of bare rusted metal that should be protected from further rusting. Three or four years outside and it will have weathering showing up again.
To answer your original question. I worked at gas stations in 1967-1968. A couple times a year the islands and pumps were painted by brush. They looked good for a couple days until someone spilled some gasoline on them then they got the crinkled paint look.

Any suggestions?

Eastwood has a rust neutralizer you can spray on then clean for paint. I have also used deluded numeric acid, not my favorite.

Your GB 176 in the picture looks the way it was when you found it. My money says it does not look the way it did in 1939 the last day it was in operation. Back then, like today, good business is about appearances and I can't imagine even an out of the way country station getting much business with equipment looking like that.
For your purpose, wire brush all of the flaking crud and brush on a coat of rust stop primer. Then paint it with your choice of colors. You can thin the paint with gasoline to flatten it up. There is a lot of tricks to "weather" the look. (just before the paint is totally dry, stick your hand in the dirt and then rub it over some spots ) Check with some of the guys that have done rust orations.

Gotta love autocheck..I got to believe you're a victim here...diluted muriatic acid sounds and looks better!

What?