Here are some more alternatives I'd like you to check. Thank you very much!
1) He was first mentioned to Marlow by the accountant. Can you also say: He was mentioned by the accountant for the first time?
2)His clothes were highly coloured. He was dressed in highly coloured clothes.
He was colorfully dressed.He dressed all in white.
3) He failed to put his ideals into practice (not to realize his ideals).
He reached the station on foot because the steamer was broken.
4) It was a depressing place with broken machinery and dead men lying on the ground.
5)The steamer he had to command had sunk (and not submeged) to the bottom of the river (OR and lay at the bottom..) and he needed to repair it.
6) The Eldorado Expedition was meant to be an ivory seek (hunt??) expedition (how do you call an expedition in search of ivory?)
7) He was regarded as a remarkable person that (or better who?) was more comfortable at sea than on land.
8) He found a message that told them (better urged him, urging him?) to hurry up.
9) He was so successful in his job because he never got (fell, was???) ill. When the other men died, he did (better took over) thir jobs.
1. Yes.
3. failed to realize his...
6. ivory seeking expedition OR an expedition to seek for ivory\
7. who
9. thir = their
Sra