My web searches had paid dividends and I have enough information to build a harpoon and norsaq (there is plenty out there re norsaq's not harpoons)

However... I am almost back to where i started as it looks as though the Aleut "throwing boards" are a form of (if not actually) an atlatl? I use this term for the fact that it is thrown with an "end" of dart fulcrum.

I have information about a "Sea Otter Dart" the Aleuts used and the throwing board they used with it.
Did they use these to the exclusion of harpoons?
If they did use harpoons did they use a norsaq type of throwing board or their own "atlatl type" throwing board?
Are their harpoons differently designed to the Greenland harpoon? Or would you call the Sea Otter dart a harpoon?

Is there any interest in me putting together a list of key resources i have found? i.e. throwing boards (norsaq) Harpoons and darts. All collected with an idea to DIY.

Does anyone want to tell me about the round ring "thing" that appears to be raised and seen on many Eskimo kayaks. It looks like my wife's embroidery circular frame! Perhaps i have asked enough questions!