Hmmm...wow, this is crazy! First of all, love the bloom, Tom. Nice growing!! I'd been looking at possibly getting this Bulbo from Andy's at some point. But, the question of which species is it is really interesting!! I don't have nearly the personal expertise to venture a guess. Even looking at the IOSPE pages for each leaves me wondering.
blumei:
IOSPE PHOTOS
masdevalliaceum:
IOSPE PHOTOS
Just from reading these, it seems that blumei can have two blooms on an inflorescence. Other than that, and perhaps some difference in their respective distributions...
Can't wait to see what other people think!