1921 D Morgan Dollar, ?

Probably nor - I don't know of any 1921-D's with such pronounced doubling. In fact, there's only one close in the entire Morgan series, the 1888-O "Hot Lips." Is it raised from the surface of the coin? I'm seeing a Dollar which has been ridden hard and put up wet, showing signs of a hard cleaning and what you're seeing could be remnants of the crud which was removed.

This is one of those infuriating things, I think, that looks like it really should be something but isn't.

There will definitely be a thickness dimension to it if it's doubling, though. You'll plainly be able to feel it by dragging the tip of a toothpick across the edge of the feature.

Just wondering with the newer pics above I added if there were any diffidence thoughts on this coin ?

That's still the exclusive province of Leroy Van Allen, whose name is part of the VAM acronym by which Morgan varieties are known.

I've never seen deliberate doubling of this nature in a 1921-D, despite having looked at thousands of them over the years. 1921's are my particular area of interest. The closeup images are a tad unclear, but I'm thinking it might be a die wear artifact. It's too large a clearance for Machine Doubling. Keep in mind, Morgans were produced in unprecedented numbers in 1921 to satisfy the demands of the Pittman Act - over 85 million of them between the three Mints. Dies were pushed to their absolute limits, and the wondrous variety of 1921 VAMs is the result.

For this to be doubling, and "extra" features would need to be of the exact same size and shape of the original.