Billionaires with Benefits - Chapter 124 - William Made a Mistake(?)

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

From the outside, Nana’s life seemed simple. She had everything she had ever wanted: a cute but rascally pair of twin brothers, a best friend, and her own restaurant. Nana couldn’t ask for anything more; she was happy and content in her life.

Gu Yanfei was reborn.

In her last life, only after her death did she find out that she was a real daughter in a book of true and false daughters.

The original female protagonist, Fake Daughter, is the daughter of luck. She occupies a magpie’s nest and is loved by thousands of people. She is the eyeball and heart of the Gu family, stepping on her Gu Yanfei’s flesh and blood for a lifetime of honor.

In that lifetime, Gu Yanfei lived and died unclearly.

After her death, she was reincarnated into the realm of self-cultivation and became a medical practitioner. She didn’t want to, but after practicing for two hundred years, she was struck by a thunderbolt back to her previous life.

Back to the time when the true and false daughter’s life experience was revealed.

When the real daughter came back, everyone in the Hou residence laughed at her with no ink on her chest and a straw bag.

But I don’t know that Gu Yanfei is now a full-level rebirth!

- Description from novelbuddy