Bonded Summoner - Chapter 34Book 5. : Champion’s Rift

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.

For his sake, she was willing to abandon her career as the best actress and be his wife. With her own network, money and unscrupulous methods, she helped him rise to the top of the world. He, on the other hand, held another woman in his embrace and kicked her away with no mercy. It turned out that all he ever wanted was her rare blood type, her six-month-old child’s cord blood. It was her life… When she opened her eyes again, she returned to her 20-year-old self. Time repeated and her life rewound. In this life, she would live well.

Quenser and Heivia came back from their one week vacation. The next stage that awaits the two is the experimental battlefield ‘Madagascar’, a huge island on the east side of the African continent. Quenser and the others have been sent to destroy the second-generation object from the Faith Organization: Trinity Style. The worst tropical night ever begins now!

Heavy Object EX chapters are being released with each volume of the Heavy Object anime home releases (blu-ray / DVD) in Japan.