Interesting, but I don't know.....the h.ulmarius I find in my area always grow on trees, and always have off centered stems:
I know they look a bit different in different parts of the country, but those don't look the same to me
The initial pics in TCO's thread, that were given to him from the source of the print, look like the h.ulmarius i know and love:
but even the ones he grew looked different. The mushrooms you have pictured there, I don't think are h.ulmarius. they tend to grow in clusters of 3-4. Possibly a type of oyster, but not H.Ulmarius
PS, great post Greysrdbest!