RE: Does anyone know what this might be?
The piston dam indicates a loop scavanged engine and was intended to give the incoming mixture a deflection up and into the glow plug and back down and out the exhaust which was directly across from the transfer port. This was the most common porting on engines of that period before the introduction of early forms of ***** porting.
Many early engines of the period that featured throttles also used the articulated exhaust baffle senario in which the baffle was articulated with the throttle barrel.
The World brand radio system puts the systems age to the late sixties perhap early seventies but check the servo plugs to see how many conductors there are three or four? The four lead systems are a bit earlier. Note if you remove the servo output are you will see the the output bushing is a square and not round. Earlier servos tended to be a long rod output from the top or ends and not rotary.
Fun to look at the stuff and if you fly the airplane do not use any of the electronics and also recomend not useing that engine unless you just want to play with it. It will be a challange.
You will find that older RC airplanes and I mean airplanes that were designed for older RC systems tended to use smaller engines than what we would use today.
John