I'm sorry for the misunderstanding, DD.

The 'Waters" book round I referred to was on page 294 of "Pet Loads". There is a picture of 5, .375 rounds, the first being:
#1 the first belted .375 designated the .400/375 H&H, circa 1905:

He also goes on to state, when referring to the 'first belted .375:

"That honour - if it be such - must go to the older and smaller .400/375 Holland and Holland, which made it's appearance around 1905 in the Holland barreled Mannlicher-Schoenaur rifles bearing the stamp "Steyr 1905" on their receiver sides." This paragraph is beside the picture noted on page 294.

It is the same round Ash pictured above, but in the photo in Water's book, appears to barely have any shoulder, almost a straight tapered case. This was due to the photo's quality only, I'm sure.