@Sdmitch: I'm testing your Subtract tool you sent me a while back and it almost works! However when the subtraction breaks the solid group into more than one physical solid then the process seems to break down slightly.
In a nutshell I need to be able to do this sort of thing:
Where I am subtracting the odd shaped polygonic solid from the cylinder.
This last week has been challenging working on the polygon tool for the foundation plugin, I've made some real progress, thanks in a large degree to the continual help and encouragement from Sdmitch, Garry K, TIG and Facer. I'll readily admit my actual SketchUp programming skills are very weak whereas my ideas are very big, it sometimes amazes me I've gotten as far as I have with these two plugins. The fact that I am able to lean on others for some help on occasion has made all the difference.