Hi Bryon...
I have to guess that your electric heat was heat pumps from the A/C's. As such, I am not sure how that would heat the basement. Again, I am just guessing as I personally not seen electric heaters in RV's other than new units with a fireplace and that is still not in the basement.
However for all I know your old coach had electric heaters in the basement. Scary I would think..but hey, if it worked.
I am not sure if GS put basement vents in all the class "A" coaches. In looking at mine, I can actually see two heat duct tubes, about 3 inches round each, coming into the basement from the floor.
I am not sure if their is one further back by the holding tanks or not, for I can not see in that area.
My next coach someday will have the Aqua Hot or Oasis system in it as I like that approach much better based on noise alone from the furnaces. But at this point, we have done so much with our 08 TM I think I will need to keep it for some time.