The stem for a ETA 7753 is the same as an ETA 7750 and is available in both 0.9mm and 1.2mm. Confusingly these are often referred to as TAP 9 and TAP 12, but this is not correct. The respective, correct TAP size is TAP 10 & TAP 7 (Google: esslinger watch stem tap chart)
As the stem you need is available in two sizes only, the smaller 0.9mm may be described as 0.9mm, or, correctly as TAP 10, or incorrectly as TAP 9. So any description with a 9 or 10 is the smaller dia and 1.2, 7 or 12 is the larger, more common size. Regardless of how they are described it should be easy to identify whether it’s the larger or smaller stem dia.
It’s much more difficult to buy a generic crown by TAP size.
Hope this helps.