Great truck, I think you should buy it. It looks older than 1923 to me, but it's hard to say. It is not a model WL. The WL was a 4 ton truck, and your floor indicates that this truck has a 1-1/2 ton capacity. 1-1/2 ton Federal trucks from around 1919 to 1923 usually have model numbers beginning with "s". Do you know what engine it has, or if the transmission is mounted in unit with the engine, or amidship? The radiator tanks appear to be aluminum, which is not something I have seen before. They are usually steel. The dash board does not look like the usual Federal dash, perhaps it was supplied with the fire equipment. It's in very nice condition. Good Luck.