It's a completely different size and doesn't fit the hole properly. He's a machinist so he made it fit. Even the pin out is shaped different. Our tool is only two years old and matched the numbers exactly. If you're going to make parts so drastically different, supply a new housing as well.
Oh, and $15 for shipping?! Really? I would have packaged and shipped that for $7 or under (i do the shipping and receiving here). $23 for an $8 part is stupid.