What is wrong with Massey Harris 30?

I have been working on a massey harris 30 and there is no spark to the spark plugs. The distributor is new and the coil was replaced about a year ago. I also replaced the ignition switch (button that is pushed in (off) or pulled out (running)). There is also a key hole but I we have just used a screwdriver to work as a key. Any ideas? Thanks