Hey Bart, you might be on to something with the "crossover hose and check valve assy". If the crossover hose ties into the vacuum pump, it would pull fumes out of the crankcase. The question now would be, where would the fumes go once sucked into the pump? The mention of a check valve assy reeks of PCV to me.
As far as apologies go, I am not owed any from you, I probably owe more, in general, than I am due.
