"to our surprise it was to small and you could see the cut of the tile"
So there was a difference between the size of the hole and the edge of the register - a common error in measurement.
Fortunately, there are companies that make custom registers - a solution a bit more expensive than measuring accurately, but available:
Google is your friend
www.heatpro.us energy businessmen's knowledge
Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.
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