Interest in device for simultaneously measuring angular change in two planes?

[William Youngs]

I live in a two story 15-sided Deltec house with curved staircase to the second floor.   I had a great deal of difficulty making appropriate compound miter cuts for the handrail.  I looked for a tool in the marketplace that would assist with measuring compound angles and was unable to find any.  Do others of you in the building trade think such a tool would be useful?  I have developed a prototype for such a tool and recently filed a provisional patent and would be interested in identifying toolmakers or investors that might be interested in working with me to bring the tool to market.  As soon as I get the official notification from the patent office I will be happy to share more details on the device.  Thanks.