Finding Gjábakki...under lava

I spent the day doing some household chores and preparing for the family reunion next weekend in Vestmannaeyjar.
I had an old photograph taken before the volcanic eruption on Heimaey in 1973 and I was trying to locate the house (called Gjábakki) where my great-grandfather Gunnlaugur and great grand-mother Elísabet lived.  It disappeared under lava during the eruption.  It was a bit tricky to find it since I had to use a special Google-map where the houses buried by ash and lava have been marked with red (and there were three houses named Gjábakki on the map) but I managed to locate it by looking at old photos.