Jameson 15 year old A Millar Bottling (1950s)

I’m actually afraid to open the bottle until I know more about it. It is a rare bottle of pure Pot Still whiskey dated from 1950s/1960s. There are no content statements for fluid or alcohol. This is what is known as Bonders Whiskey ie brewed by Jameson - sold in barrels to Dublin grocers who bottled it - labels supplied by Jameson and the shop would type it’s name as bottler. A.Millar was located in the Liberties - Thomas Street in Dublin. Third party bottling ceased in mid 1960s. I believe the bottle is worth €1,000 to €2,500. Would love to know more about it, have given it a 5 in the interim (hope it is that good)