Building an empire which the sun never set - Chapter 68: The Visitor

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.

When I was reborn in South Korea, I wanted to live my life in peace. Pass the activation system, unlock the 'Big Brother' career, obtain the invincible system, and embark on the road to power

After Chuzheng is suddenly pronounced dead by a system all of a sudden, her only worry in life becomes—spending money. Ever since she gets stuck with this system, her back is no longer sore and her legs no longer ache. Heck, there isn’t even a time when she goes out of breath.System: Let us set a small goal first and squander a hundred million… Little Miss, stop right there! Don’t activate the invincible mode!(▼皿▼#) Chuzheng: Can you please explain what is this thing that is leeching off me?Random Thing: Babe, you can do whatever you want to me.Chuzheng: (touches her blade) In-In that case, I will not stand on ceremony.System: Little Miss, please put the saber down right this instant! (▼へ▼メ)#LittleMissAlwaysDoesAsShePleases.

Qin Lin was electrocuted by playing a nostalgic “Ranch Story” game, and suddenly gained the ability to enter the game. He also found that he could bring the watermelons grown in the game out of reality.

At first, he calculated that a pound of watermelon would sell for 2 yuan. As long as he sells 10,000 catties of watermelon seeds in the game, he can earn 20,000 yuan a day.

Later, he discovered that by upgrading pastures, he could obtain advanced crops beyond the world, raising livestock to obtain advanced livestock breeds that were far beyond the world, and building factories to obtain various formulas that were far beyond the world, and everything was different.

- Description from novelbuddy