Do you have the book &quot;OLIVER photographic history&quot; by April Halberstadt?  If so there is an excellent picture on the front cover that should help you with the general layout of the cultivator on a #70.
 Sounds like you are a couple of pieces short which can be frustrating. It will work without the springs and as for the cast bracket under the rear pipe, you can wire the center gang up temporarily until you locate one. You have a good excuse to attend the winter get together and inquire for parts and still be ready to 'head to the field' in tme to cultivate.
                               Keep tryin'  (and keep buyin')