The bike was built by Mr Reid of Birmingham circa 1937. The blower is a Centric, Type 125A, fed by a TT Amal on the RH side between the gearbox and magneto. You can see the pipe leading from it to the blower, where it crosses in front of the magneto. Boost was limited to 8lb*in^2. The pale color of the heads is due to an 'aluminized' finish to both them and the cylinders. Details via Oct 28th issue of The Motor Cycle.
-Doug