Gravestones & MI's are public documents - anyone can photograph them and publish such photos - eg I have a representative collection on my CD-Rom and many more in my own private collection - that said I'm sure that many are very grateful that you are willing to photograph them - most Island MI's have now been recorded and published by the IoMFHSoc - It is possible that these publications may be available on Mormon microfilm (I know that Noreen Cottier used to send copies to SLC).