[78-L] Canadian Columbia Double Disk promo record

[agp]

I was digging through my stuff today and came across a disk that I 
have a question about. Its a Canadian Columbia disk. I think it would 
have been a promo-special. The catalogue number is P-11 and its says 
'patriotic series' on the label of the a-side which is Land of the 
Maple by Prince's Military Band. The b-side is a special Columbia 
label saying that the disk is to be sold at a price of 30 cents. The 
content of the b-side is a talk extolling the virtues of Columbia 
double disk records, with some musical examples.

So, the question is about the date of the item and any background in it

Tony