Jameson 15 year old A Millar Bottling (1950s)

I'm hesitant to open this bottle before learning more about it. This is a scarce bottle of pure Pot Still whiskey from the 1950s/1960s. It lacks statements for volume or alcohol content. This is often referred to as Bonders Whiskey, meaning it was produced by Jameson and sold in barrels to Dublin grocers who then bottled it. Jameson provided the labels, and the shop would add its name as the bottler. A. Millar was a business located in the Liberties area on Thomas Street in Dublin. Third-party bottling ended in the mid-1960s. I estimate the bottle's value to be between €1,000 and €2,500. I would appreciate more information; in the meantime, I've given it a 5 (hoping it lives up to that).