Jon
Make sure you're selecting the dimension (the one which specifies the gap between you're cut-extrude sketch and the model edge) instead of the base feature edge, for direction 1.
Also you need to make sure that the inclined sketch segment in your cut-extrude sketch is parallel and...
Use "Split Part" and save individual bodies as parts. Then RMB on the "split" feature in the Feature Manager and there you'll find an option to create an Assembly.
Regards,
--Veera
From your query I presume you are using SW2004. You will find the split option when you right mouse click on a cell/row in the Hole Table. Once split you can drag and rearrange
--Veera