To fit a hand throttle?

I have a 2.25 diesel, was once a petrol so has no hand throttle. I want to keep the landie original, so have fitted older type mirrors, wheel rims etc, but would fitting a hand throttle be a good move? How does it work in conjunction with the frankly WEIRD "sleeve operating" throttle cable?

It will be in keeping with tradition, as they were factory fitted on diesels. Are they easy to install?

Do you have a PTO? If not a hanfd throttle would be pretty pointless.

What!!! It's called cruise control!