I would have gone with you Chris. Looks like an O-suriage tachi from Muromachi period. But Ken points a puzzling detail about the drilled mekugi ana (the last one being quite recent by the way), so I'm lost. And I see some hada (itame with some loose grain that might be mokume, hard to say for sure).
So, I have doubts and lack expertise but I'd say Muromachi. Of course, I'm probably 100% wrong!
EDIT: On second thought, probably too much tapering for Muromachi, so shinto is probably right, though it's not the usual Kanei or Kambun sugata.