I have been challenged to wear a bullet bra under a tight sweater for the New Year (like Marilyn Monroe or Jayne Mansfield, but not that I could attempt to come anywhere near their boob projection!).
But the sizing seems problematic. These bras are of cotton and don't stretch like modern ones.
For modern elasticated bras, you measure round your ribcage, and that's the band size. Then you measure over your boobs, and the increase gives the cup size: 1" more is A cup, 2" more is B cup etc.
I now measure 38/41, making me 38 B or so, and modern bras of this size generally fit me quite well.
How can I translate these measurements to a non-stretch bullet bra?
There is a secondary issue, which had not occurred to me until I read about it. That is, in a bullet bra, the breast tissue was forced into the cones and the boobs were moulded to the pointy cups.
So for normal women, the cups perhaps needed to be a bit full to accommodate their breast tissue. I am a bit long and pointy, as a result of my nipple pumping regime, so I might well fit into a conical cup quite nicely, and for me, a pointy bra cup might be really comfortable, allowing me to wear my nipplefunwear teats quite securely.