RE

.....Along about the same time, some guide, turned boat builder started
publishing articles in Fly Tyer magazine....... and a Zap a Gap glue
gun !

I've had a fair amount of experience with guide's who turned boat
builder,
and Zap a Gap and Glue Gun flies. I can tell you without hesitation
not to trust anything those glue-gun-fishing-guide boat builders have
to say. Theyr'e all liars.