I need help identifying this a/c

Earlier today I was outside doing chores when I heard that sound that can only mean a non-civillian aircraft will soon be passing close by overhead. I saw an aircraft about 2 miles away, but other than being able to tell it wasn’t civilian, I couldn’t figure out what type it was. about 5 minutes later, 2 more came almost directly over my house, followed by one more a couple of minutes later. By the time the 3rd one went over, I had my binoculars out, and I got a pretty good look at the last 2. They were all the same type, and they looked kind of like A/B-26s, except for the horizontal stabs, and the nose. The tail and wings were pretty similar looking to an A-26. The nose looked more like an OV-1 type, and the tailplanes were slightly swept back with pretty high dihedral. The 4th a/c was painted in a red/white scheme similar to coast guard and naval training aircraft. I looked in a couple books, and I think they looked like Grumman S-2 or C-1s. Am I correct? One more detail- the engines had a distinct flutter sound to them that I haven’t heard in aircraft engines before, kind of like the sound of a distant harley-davidson…

Hey josh, does this sound like what you heard?
the S-2 is the second on the list.
I looked at some photos and the Tracker has a “chubby” fuselage. Do you live near any forrest/wild fires? I think some trackers got converted to firefighters…

Sounds like CDF (California Department of Forestry) Trackers.

Take a looksee here and see if these are the birds…

Fade to Black…

that’s what the planes looked like, but they had a different pattern of red/white. Probably were USFS a/c though, since there’s a few fires somewhat near where I live. Thanks!