If it's the old plastic frame one, the flanges are bigger. This is typical of most Life Like models, plastic frame or split frame. I don't have one of the newer GP-38-2 models, so I can't speak directly to that, but it wouldn't surprise me if the wheels came from the same parts barrel.
They're easy to turn down, just put a couple of flat files next to each other and apply track power to them. Run the engine until you see a nice even flat spot around the edge of the flanges. Test run it periodically.
After doing this, it's a good idea to do a complete tear down, clean and re-lube to make sure there aren't any metal shavings floating around.
Lee