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Well, I found this earlier today, and I'm not really sure what they are. Based on the appearance and spore print, I think that they might be Kuehneromyces mutabilis, but since Galerina marginata supposedly is very similar I wonder what you think.
They were growing on a fairly fresh birch stump in a mixed forest with mostly (almost only) birch and pine. The cap is yellow brown, hygrophanous, and on some mushrooms has a "hump". On some not. The biggest cap is about 4.5 cm in diameter. The gills are light, but on some of the mushrooms (which I have in my fridge) they have become dark, maybe because of some crushing..
The stipes are scaly, especially visible on picture four. They are light in color at the top, becoming darker further down. A thin brownish (probably from the spores) veil is present on many stipes.
Young mushrooms have a white veil.
The spore prints I got were light, but they are brown. Definitely paler then "Agaricus brown", but I can't really specify the color.
Those look like Kuehneromyces mutabilis to me, too. They are, as you stated, very similar to the deadly Galerina marginata. This species has a scaly stem where the Galerina has a fibrillose one.
Because of the similarity they are usually avoided. The risk involved with an error is so high that it hardly seems worth it.
Something you could try would be to perform the Meixner text for amatoxins with them. Squeeze a drop of juice from one onto a piece of newsprint. Draw a circle around the drop with a pencil and also make a control circle, and label both. After the drop of juice has dried, put a drop of concentrated Hydrochloric Acid (sometimes sold as Muriatic Acid) on each circle. A positive test for amatoxins is a bluish to purplish color in the test circle and not the control circle. If the control circle turns to that color then you need to get a different source of newsprint for the test. It is *very* sensitive (to levels well below micrograms) and will give false positives but not false negatives.
I wouldn't bother eating them. Even if I'm really sure, the cost of a mistake is just too high. They'd have to be pretty wonderful eating to make them worth that risk.