After struggling for so long with this scenario, (going bankrupt, getting fired etc), I finally managed to get Gold on Medium. I think the key trick is to ignore trains until around 1997, and focus on Industry, since this is a guaranteed profit (and you start with $4.4M, which is enough for a few industries from start). The AI all failed, though not all went into liquidation or got fired, however the Benin and Abidjan both went into liquidation and I think the Senegal Railroad got fired, if not liquidated, making things easier.
I only started on trains once Abidjan-Niger went into liquidation (which was around 1995 I think, and may even have been before the Benin Railroad, despite me thinking the Benin Railroad being most likely to fail). By game end, I had around 5,000 miles of track, consisting of the 5 AI's layouts and a few connections to other coastal cities (as well as Abuja and Niamey). The Nigerian Railroad did create a new company after I merged (he did not get fired), which was also merged (in Liberia I believe, but may have been Sierra Leone).
Not sure how things would have gone had I been on Expert, but it was actually very simple on Medium, I was making around $8M profit a year (this might have been in a boom though) by end game, and had all Electric Track (although I used a few Diesels). Game was won by 2003. All in all a very nice and well made scenario.
![Very Happy :-D](./images/smilies/icon_biggrin.gif)