Oooh, I like this! There are elements in this fic that I typically don't care for, and yet you've made them work here. In particular, I don't generally buy into a suave, wealthy Snape. But you've made it feel plausible in this fic. And the whole thing is a nice twist on the usual "Snape seeks Lucius' patronage" scenario.
I got a giggle out of your reference to the Malfoy estate as an "ancestral heap." And I loved that, now that the war had ended, Snape was able to flat-out state his opinion of Draco. An "arrogant little shite" and an "obnoxious little toad" indeed! ::snicker::