Way too simple for such an expensive tool!
If you can provide dimensions I will get one made for you. But it will cost you to keep doing what you are doing on this forum!
Jon, do you have a picture of the tool that you made? You could make a better one out of plumbing parts.
What about using a metal pipe cap (black or galvanized metal) or a metal electrical box cover plate? You could drill holes in it then insert bolts to press it in without hitting it. Is the correct tool an OTC 7786?