I just watched a Youtube video about a Top Bar hive built to accept a Langstroth body stacked on top.
I'm no expert, but allow me to comment.
In order to accept the super, this guy had to use top-bars with gaps between them. One of the [usual] principles of top-bar beekeeping is the fact that the bars have no spaces between them. This preserves nest climate better, does not alert the bees when you take off the lid, and makes a crown board entirely superfluous. Having gaps between the top-bars negates all of this.
I suppose one can use mostly closed top-bars and use a gapped top-bar every 5 or 10 bars, and still get the bees to "go up" into the super. Just hope the queen doesn't accidentally go into the super, or else she won't find her way back down again. So, nothing wrong with using a queen excluder in such a scenario, then.
Since this guy's supers take the same frame/top-bar size as the top-bar hive itself, he had to make the top-bars shorter than the width of the trunk of the top-bar hive. This is also rather unusual for a top-bar hive -- most top-bar hives have top-bars that are longer than the trunk is wide (this makes inspecting and manipulating the frames easier, and it makes the crown board unnecessary).
Essentially this guy doesn't have a classic "Kenyan" top-bar hive. What's he's got is a Langstroth hive with sloping sides in the bottom box and no frames in the bottom box. There's nothing wrong with that, of course, but I don't see how he would be able to practice standard top-bar beekeeping in it.
My thoughts:
http://bushfarms.com/beeshorizontalhives.htm
http://bushfarms.com/beestopbarhives.htm#ttbh
I visited those two pages, but I can't find anything on them related to twd72's question. Could you tell us here, in a little more detail, please?