it dosnt look like a red jungle fowl, it has the same feather color though. It might be a welsummer or it could be a red jungle fowl hybrid, it could also be a copper maran. hope this helps
True Red Junglefowl have really long, slender, greyish blue legs and aren't at all 'dumpy' or 'chunky' (sorry for describing your bird as dumpy and chunky)
They also have long, pointed, central tail feathers and their feathers look generally 'neater' than your bird (sorry again - All I seem to be doing is offending your rooster !)
Have his wings been clipped?
The ones in Hawaii are crossed with something which gives them pink/yellow legs. perhaps it could be from that line but I think the lack of tail feathers reduces that possibility somewhat.
So all in all I've no idea what he really is (apart from annoyed at my description of him
Honestly he could be a few different breeds, and or mixes. I had a Brown Leghorn who was larger than standard called for, and identifical to yours. Though usually they aren't quite as heavy bodied? I would say he's not quite pure either, very possibly a mix of Red Jungle Fowl with Welsummer or Leghorn.
He is gorgeous though, I love roosters like this. *sigh* makes me miss my evil boy Elvis.