What type of oil to use...10w40
As to the horns, that is where they were when I bought the bus, perhaps to make them louder?? They certainly are that...
Looks like the recess for the horns has been removed to better utilize the space in that compartment. BTW, air horns on top of a bus might look good, but are not nearly as effective as horns close to the ground. Air horns up high will project their sound over the heads of those close by. Having the horns lower lets the sound bounce right into the ears of those who need to soil their pants.