Thanks tschmid.

FWIW, the Ilford Multigrade 500H is not a color head, but rather a VC head, using 2 halogen light sources that are reflected through a diffused mixing box. The VC filtration is then controlled on the timer.

After some research on the net, I've come to the conclusion that the only alternative would be to use the Aristo. They have a model specifically made for the 138, and even offer the power source in 220V, which also offers a similar VC filter control as the Ilford System.