"even though it seems the trend in modern Irish is to pronounce Aonghus like (ayn-gus) in past times it was pronounced like (in-es) hence we have Maginis or Guinness...the same happens with many other (sur)names in Irish...Ferris is another example"

would I be right in saying this? or are there places where Aonghus is pronounced with gh silent?

Lá mhaith agaibh ar aon nós!

Ó Thuaidh, creidim.