Age Of William Whiteley House Of Lords Bottle

While digging on our old family game farm in South Africa, I found a 750 mL bottle of William Whiteley House of Lords Whisky (embossed on the glass bottle). The bottle is empty and has no label. On the underside there is Whiteley Liquor bottle Scotland 5834 and some other fairly illedgible writing. The 'ring' of a metal screw cap remain on the neck of the bottle. Do you have an idea of when this might have been produced? My late grandfather was a famous whisky drinker and I'd just love to know when he might have bought this bottle. Thank you so much!