Previous Grimauld Place & Inheritance Discussion

[ghinghapuss]

No: HPFGUIDX 88017

Mandy here:
Even if Harry inherits Grimmauld Place he can't legally move into it 
alone until he is of age after the series has finished.  Which is 
unfortunate, because I would like to see him inheriting Grimmauld 
Place, moving in to be away from the Dursleys in his first attempt at 
independence, and have LV come knocking on the door with a piece of 
coal and an AK for his new home. 

Which got me wondering just who is Harry's current legal guardian? 
The Dursley's right?  Sirius was named his Godfather, and the role of 
Godfather is to assume the role of parent if the parents die, but 
doesn't a God parent have to legally adopt the child to assume that 
role?  We know Sirius didn't have the time to adopt Harry as he was 
in prison, a fact that would disqualify him form adopting a child 
anyway.  So I assume the Dursleys have legal control over Harry until 
he is 18.  Now this all applies in the Muggle world and not the WW of 
course, but surly a wizard, even one a powerful as DD, couldn't place 
a baby with a muggle family without having that muggle family adopt 
the child legally?  The local authorities would soon get suspicious 
if children started popping up in communities from goddnessknows 
where.  But then again the WW seems able to pull the wool over the 
Muggle worlds eye's most of the time.

So it looks like the Dursley's are Harry's legal guardians, so if 
that's the case and Harry inherits Grimmauld would the Dursleys have 
temporary control over the house until Harry is of age?  What would 
they do with it?  Sell it? Would latent witch Petunia use it?