I have found that the old style two-piece telescoping box goes into the 12- prefix when it was replaced with the red/white hinged box.
So 11- prefix guns have the following boxes...
The RST4 had a 2-piece red/black/white box with black end and white info on the end.
The RST4 had a 2-piece red/black and white box with "RUGER PISTOL 6" BARREL" on the end.
The T512 is 2-piece yellow/red/black with a red end that says "RUGER MARK I" on the top of the left end, and T512 as the catalog number on the end.
And the box for the T678 looks like the T512 box except only has "TARGET PISTOL" on the end without mention of catalog number.
Chet15
At one time I had a Ruger Standard 6in. barrel Auto RST-6 with walnut grips, serial number 11-9780X. It came in a 2 piece Old Model telescoping MK-l box, with a 6 in. RST-6 sticker covering up the MK-l label. I guess Ruger ran out of Standard boxes and used what ever they had.
Over the years, I have learned that when Bill Ruger called the shots, nothing was wasted , hense the term was coined: "never say never" when Ruger oddities are encountered. Boxes were mixed, parts mixed. And so forth and so on. The world of Ruger. I never cease to be amazed, even after all the years that have passed.