Actually, in 1981/1982 Sirius wouldn't have been the oldest male in the family. Both of his grandfathers (who were both Black's) were still alive, so all of this is rather convoluted anyway. Additionally, Orion put a clause in which rendered the contract sealed beyond his death.
Sirius and Ellie will find a way around this, but it's not for a few more chapters. Thanks so much for reading and reviewing and for your excellent question.
Excellent Chapter! However i have a question. Even if Walburga Black is alive, Sirius is the oldest alive male of the black family - the Heir. Isn't it possible as male head of the black family he can dissolve his marriage as well as control the black family fortune.