Primordial Soul's Rebirth - CHAPTER 384 - Shirozan.

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.

She is an expert in medicine, the only daughter of Yun Tian, Yun Valley’s master.

Her parents died, leaving her alone in this world. She fell from heaven to hell. She had a marriage prospect but her future husband broke it off. The entire world view her as a joke.

She blossoms in Feng Yun Hall, with unparalleled wisdom and startling beauty.

Against all the people eager to make a move, she lifts her hand first. Kill the chicken to warn the monkey.

But nobody knows that the soul within her has long been replaced by someone from another world.

She has no regret in the past life and originally plans to live an idyllic life, but because of the same question from the past life, she gives up the peaceful life and steps into the power struggle for imperial power.

- Description from Novelupdates

Mo Han was in a tough spot. His daughter, Chen Chen, needed a lot of money, three hundred thousand, for an operation to treat her leukemia.He didn't have the cash and didn't know what to do. So, he tried to come up with some sneaky plans near a bar, hoping to raise the money that way. But things went from bad to worse when an old classmate who had rejected him in college caught him red-handed. She made fun of him and made him feel even worse.When Mo Han's wife, Luo Ning, found out about the situation, she rushed over with Zhang Hao, who had a crush on her. But instead of helping, Luo Ning shocked Mo Han by suggesting they get a divorce! And just like that, she left with Zhang Hao in a car, leaving Mo Han feeling alone and confused.After a night of heavy rain, something amazing happened to Mo Han. He unexpectedly inherited something really special from someone called Ye Lingfeng, a fallen medical expert. From that moment on, Mo Han's life took a turn. He decided to take charge of his own destiny and set out to change the world, no matter what challenges came his way.

I returned to the past to become an actor, instead I reincarnated as a Third-Gen Chaebol (rich conglomerate family).[Winner of the 7th Korean Web Novel Competition]