I can't say for the 300G but on the 300F I've seen most period pictures showing one on the passenger air filter slightly canted out to the side. Check out this advertisement -
https://300f.com/media_ad03.htm
I also have a copy of the Tom McCahill "Car Owner Handbook" where he shows a lot of pictures of the 300F. In one it shows the decal on the passenger air cleaner as above but in another it's turned inward. But you can also tell that the air cleaners are not installed properly in that shot. -
https://photos.app.goo.gl/r7FDPZyYT34jMV1y6
In both these cases I didn't see one on the driver side. I know people always put two on and it would make sense to have one on the driver side. In general, Chrysler faced the air cleaner decal toward the side of the car where someone servicing the engine would see it and not straight ahead. Usually toward the direction of where you would add oil to the engine.
Nick.