Regarding St. Lappan, I looked him up and he is hard to find information about, I will look further!
So far I think he is from the 8th century Ireland, based on one parish showing him as the founder in Donore in the 8th century. I also found another Irish saint described as a son of 'Lappani' perhaps an alternative name spelling? It would be good to know those to possibly find out more!
Are you from Ireland Tom?