Optocoupler for channel switching

[dsones]

Hi:
I'm building a princeton reverb II clone and running into things I haven't encountered in other builds.  There is a component (vactec led/ldr 013556) that is used for channel switching.  I can't find an original vactec or any info on what the values need to be for the optocoupler.  Does anyone know what is equivalent to (vactec led/ldr 013556).  I also notice the push/pull pots look unusual (like two pots connected together).  Anyone know the what substitution pots might be?
Thanks,

[acheld]

It has been said that a VTL5C1 will work in those positions, but can't confirm as I don't have the specs for the 013556.   

[tubeswell]

You might want to use relays for channel switching if you can’t find any vactrols (Vactrols that are made with cadmium aren’t allowed to be manufactured since RoHS).