Wanted to update this thread for the 4 others that may find it interesting. NYRifleman kindly sent me a link to a beautiful 7 mag supergrade that showed up on GB today. Assuming it’s all original with the original stock (from appearances it seems to be) it’s the earliest black tip supergrade I’ve seen - G37673. Helps to delineate the progression; even if the changeover was gradual.

[Linked Image from i.postimg.cc]

[Linked Image from i.postimg.cc]