Here's my result from updated scenario (I played with no breakdowns mod):
Finished in 6 years, 8 months ...
I started by building coal/iron ore to steel mill network in northern part of map and filled it with trains. I had to make a maximum bank loan, but was able to repay it by the end of 1950. Once I had some steady income, I have built tram networks in hamlets to encourage city growth, and connected all cities with a dual track network (clockwise and counterclockwise tracks). These intercity trains didn't make much profit first, but managed to cover their expenses around 1954/55.
Next step was building grape/winery network, connecting five wineyards in northern part of map. This was a mistake, most routes didn't make decent profit until later when 3 trains per route could rotate without waiting in the stations. This is the cause of stagnation in 1952/1953.
In 1953, I tweaked the coal/iron network and added the steel mill to factory connection. By this time, the income was around half a million $ monthly - more than I was able to spend by building new networks and buying trains. I electrified all tracks by this time and changed most of the trains to best electric model available.
Next large project, started in 1954, was the coal/iron to steel mill network in southern part of map. Large part of this network (mostly return routes) was built underground, and it seems to be more efficient than in case of it's northern counterpart, which is built completely on the surface. During 1955, my income quickly raised, and the rating got to 90%+.
By the start of 1956, I had rating of 99,9%, but didn't finish the challenge until September. I was hoping to get over the limit by tweaking the network for a few months, but it didn't seem to help much. I started to build new grain to food plant network, but won the scenarion before any of these grain trains left it's station.
The cities didn't grow much so far, my highest population city was Gotham (506) ... None of the cities accepted mail nor food nor goods by this time, but there is still plenty of time till the year 2000

Train speeds were mostly limited by wagon speed, fastest iron/coal car around could go only 60 mph ...
I'll continue building this map untill 2000 to see how the cities can grow

I hope to see more results !
/Sairait