Just completed this Williams upgrade and thought I would post some pictures. Upgrade to PS-2 with smoke added to both Lead and Trail A unit. Interesting upgrade on a traditionally NON Tethered Engine.
Also the solid fuel tank had to be drilled so the speaker could be added to the fuel tank to make room for the smoke unit. Had to drill the pilot to allow the coupler wires to pass through, but the MTH couplers fit fine.
Used a slave board in the Trail for smoke, light, coupler control. G