Hi Eon, It does ring a number of Rus. Sp. bells.
Are you able to get a picture of the underside?
Do the gills attach directly to the stipe or is there a gap?
It the top 'slimey' or rough?
If you crush a piece does it stain black, brown, or yellow?
No rusellas taste good, and some induce instant vomiting.
here's a taxonomic link;
http://www.svims.ca/council/Russul.htm