Brass transport plug id help

[Eion99]

Hi, Can anyone help with an ID on this plug. it is brass but the copper has leached out making it look solid copper.
Cheers.

 

[TimG]

No. 17 Mk. I
M - Metal (Brass)
GY - Leaded brass, not to be used with shells filled Lyddite or Shellite.
S.H. & S - Samuel Heath and Sons, Ltd., (Brass founders) 100 to 118 Leopold Street, Birmingham.

TimG

 

[Eion99]

Cheers that's great thanks