I dont think the spangle is opaline... just has some color in her wings like alot of spangles do. Your male is a sf domanant pied grey with opaline though
If you bred them you should get half single factor spangles yes. As far as colors violet and grey are both domanant color adding factors that can be in green and blue birds, and a bird can be single factor or double factor depending on if they got a gene from both parents or just one.
If the violet hen is a single factor half of the chicks will be single factor violets and half normal. If she is double factor violet all of the chicks will be single factor violets.
If the grey cock is a single factor grey half of the chicks will be single factor grey and half normal. Or if he is a double factor grey all of the chicks will be single factor grey
More than likely you will end up with some beautiful combinations of both grey and violet spangles