Strongest Kingdom: My Op Kingdom Got Transported Along With Me - Chapter 115: Assassin Vs. Mage

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.

Zhou Yu, a reclusive otaku, who did not like to go out of his house, was one day forced out of his house by a series of unexpected events.

- Description from Novelupdates

The antique market that is filled with treasures and trash.

In the highly anticipated release of the first-ever VRMMO, Yeager found himself mysteriously traveled back in time. He is poised to rise to the summit and achieve the impossible. Armed with years of gaming experience and a wealth of strategic knowledge from the future, Yeager believes he can bring about the miracle of immortality. But just as the game begins, fate takes an unexpected twist as Yeager finds himself transformed into a young woman. In a tale that challenges identity and defies the limits of virtual reality, join Yeager on a mesmerizing journey of self-discovery as he navigate a world of mysteries, battles, and alliances, all while grappling with his newfound femininity.