Old AC 2-Row Drill Planter

Irecently bought a very old 2-row AC corn planter (I believe the correct name is  "Rear Mounted Drill Planter").  It appears to be in very good shape, and includes the row markers.  I'm in the process of repainting it with my son, to teach him some basic painting skills and make it look pretty.  Probably not worthy of a restoration project, as it has an aftermarket (i.e., home made) 3-pt hitch assembly added to it. We hope to use it to plant a small amount of sweet corn in a few weeks.  I purchased a manual online so I could read up on how to properly set up the unit - specifically, the sprocket settings needed to get desired seed spacing.  If I am reading the manual correctly, it appears the closest seed spacing is rather large - like 9" or so?  Does this seem correct?  Also, the seller said the shoes were a bit worn and would likely need to be replaced soon, but they do not look markedly different from the shoes on an old JD 2-row planter I have (worn yes, but certainly appear to be operable for the small amount of corn I expect to plant (~1-2 acres each year). If I do need/want to replace the shoes, can anyone suggest a source?  Seller said they used to make their own replacement shoes, and I'd be willing to try the same, but would need dimensions/pattern to do this.  Anyone know the dimensions or have a pattern? I'll try to upload a pic of the shoes when I post. I'd upload a pic of the entire unit, but I do not have one.  Thanks in advance for your help!