You are on the right forum. An easy way to find parts is by simply entering the part number into Google search. Many times you will find what you need.
I just entered the Spring part number 180998M1 and the plunger rod part number 181052M1 into Google and immediately found places I could order them. Didn't have such immediate luck with the spacer but I know they are out there.
You will need a service book because you will need to remove the top cover to install the parts. Don't just take out the bolts and pull the cover or you will break your control valve, you must disconnect it from the pump first.
The pictures show what the underside of the top cover on a TO30 looks like.