I'll have to check tonight the lensboard tonight (if I can find it). I also use a Opemus 5a ,so it wouldn't be too hard to check. I can't recommend the 2 over the 5.
Did you get a timer with it, I popped the bulb in my Meochrom head with a normal timer, now I have to use the condensor head. So make sure about the voltage of the timer you intend to use with it (maybe someone else can chime in here regarding timers for Meochrom heads)
Unfortunately, I don't know of a source for a neg carrier for the 5, locally. But I'll keep an eye out.