[CynicalBear]

>>.Catholics wrote, rather transcribed and interpreted, scripture.<<<

No, they changed the words as illustrated in the Genesis 3:15 example and they did so throughout scripture.

[Campion]

The Jewish Publication Society (1917) translation of Genesis 3:15 (note that the subject of "shall bruise thy head" is plural, not masculine):

And I will put enmity between thee and the woman, and between thy seed and her seed; they shall bruise thy head, and thou shalt bruise their heel.'

Biblegateway.com has the RSVCE now (way cool!) and you might take a look at the footnote on Gen 3:15. The direct link is here.