Newfoundland 15c Air Mail Triangle

Here's an interesting item. 15c Newfoundland Air mail triangle stamp, showing airplane flying over industrial landscape, possibly the paper mills in Corner Brook, NFLD. I have seen four different varieties: 1) red centre with black frame, 2) red centre with blue frame, 3) black centre with blue frame, and 4) blue centre with blue frame. Can anyone provide more details such as maker and year?

I have never seen this NFLD airmail in any catalog. It is possible one of the fantasy or private post issued? I have a couple Nfld/ Labrador that are US stamps with map showing that they were US possesions. Those are actual forgeries that were stopped by the RCMP . There are Nfld fantasy issues showing zeppelins as well. None the less I'd like them in my collection just for fun. Interested to read more on this.

The stamp is not listed in the Scott Classic Specialized catalogue.

I have some other questions about Newfoundland "air post" stamps in my collection, but don't want to barge in on your thread, so will start a separate post.

I looked this up in my Triangle specialty catalog & it is not listed!

Thanks everyone for searching for this toughie. The quest goes on...