I too am thinking of the same project and am wondering if you have had anu success. I've been helping others do genealogy research and have come across many badly worn gravestones. Taking a rubbing has had almost no success. I would like to find something that I could assemble myself in order to save money as I am doing this without compensation. I have seen many handheld scanners that look like they have the right idea but they are very expensive and I do not know if they would be able to record the fine detail to read a stone that is worn to the point that it is unreadable to the naked eye. Some use lasers and others just light. Any suggestions or information on the results of your search would be appreciated!