Trying to get some expert opinions on this bird.  

Over the last week or so I've had some interesting Juncos showing up at the feeders.  At least one, possibly two cisomontanus ssp.  One for sure adult male, and a grey-hooded probable female.  Along with those has been this junco with faint white wing-bars.  White-winged ssp. is not typically a vagrant, with no reports east of the MIssissippi on eBird except a 1994 sighting in Massachusetts.  I have written it off as one of the rare Slate-colored that have some wing-bars.  It still looks odd to me regarding its grey color.  Finally I managed a very rough shot of its tail feathers.  This is where it gets interesting now.  It has 3+ tail feathers that are completely white.  I cannot find out how often that occurs in Slate-colored.  I'm going to post/host some photos and see if I can't get some third-party confirmations.