I've been checking out the various scroll vendors and some scrolls seem to not be available. I figured I'd make it easy and post what npc would match with it being sold.
Greater Heroism:
Enevold Uderford, he sells heroism.
Codrin Varzaru, he sells heroism and the spell is within the level range he sells.
Mass Haste
Blaise Acursius, transmutation is a NPC focus
Arjan, transmutation is a NPC focus. He sells other level 6 spells so it's not too high level to be on him.
Also odd is the University scroll vendor sells iron bones. Despite being a conjuration spell, the spell only effects undead. It might be better suited for La Bibliothèque Obscure.