Thanks bugzy for the support.
I had a strong feeling about the gearbox that it would need to be replace, but didn't expect that it would be so soon. The issue with replacing the gearbox is that the entire drivetrain would need modifications which includes 4x4, axle shafts, drive shafts, differentials, and engine adapter.
A strong contender for gearbox is Diahatsu Rocky 5 speed with hi lo 4X4. The differntials remain a question as currenty the rear diff is noisy, and matching it with a new gearbox is an unchartered territory
The suspension needs some oberhaul also, such as seals and rubber. The vehicle is very stiff from the rear, so would need to take 1 spring out of 2 on each side. Need to add longer front springs to balance out the ride and support additional weight of the diesel engine and winch.
Once I am upgrading the drivertrain I will also install power disk brakes, power steering, and bigger radiator.
The only fixing up I have done is that I got the front and rear seats poshished with Beage Leatherite.
Body modifications will happen after completion of the major mechanical modifications. I must say the jeep is a head turner without the hood, and it brings smiles to people's faces