I don't remember the particulars, but there is a guy who goes back in time to a different family, seduces them, and along the way goes into either medicine or engineering and becomes incredibly rich.
I don't remember the particulars, but there is a guy who goes back in time to a different family, seduces them, and along the way goes into either medicine or engineering and becomes incredibly rich.
Rebirth by John Wales & Wires & Dr. Stan
https://storiesonline.net/s/54677/rebirth
https://storiesonline.net/a/John_Wales
https://storiesonline.net/a/Dr_Stan
Is it the one where the MC dies some way and wakes up in the body of a 17 year old boy. Winds up having sex with mother and sister. They develop ESP and wind up having other adventures. Two stories if I remember correctly.
Could it be 'Fountain of Youth' and 'Fountain of Youth Book II" by Lazlong?
https://storiesonline.net/s/40992/the-fountain-of-youth
https://storiesonline.net/s/41823/the-fountain-of-youth-book-ii