Heath Copper Mixing Bowl #089/300

I purchased this item at an Estate Sale, I have been able find very little information about it online. It is stamped - Heath 089/300 - it's very well made and in great condition. I would like to find out where it was manufactured, when it was manufactured and what the numbers mean. It's approx. 6" deep and 9 1/2" in dia. shown is the condition I found it in. I haven't cleaned or polished it. I just thought it was a really great looking bowl and it being numbered intrigued me..

Any info would be appreciated...

Thanks
Jackie