The piece that is missing from the starter is the part the starter rope should come through. This starter cover is reversible so that the engine can run in reverse. It's one of those pieces that I will endevour to obtain. At the moment it is extremely easy to brake the rope. That's experience talking, 4 times in 2 days!!
As for the rest of the parts, I was lucky in that the machine was complete, and as I disassemble with care, there was only one bolt that sheared off. It may sound drastic, but I also make use of an oxy/accetylene set to dismantle old equipment. Not to cut, just to break the rust.
With my trade being a Fitter/ Machinist with small engine qualifications, I have performed many restorations over 35 years, of all types of items, and have many techniques that help the job along. I do all the work myself, and have almost all tools and equipment that are needed to complete the task.