'Nineteen hundred' is most commonly used for thousands of years. 'One thousand nine hundred' would be used when referring to other values e.g. I have one thousand nine hundred and fifty dollars; he was born in nineteen hundred and fifty or he was born in nineteen fifty. Is it ever shorten like this in Spanish i.e. el ano novecientos cincuenta?
The date in the original Spanish sentence is "mil novecientos cincuenta" directly translated that is 1000 900 50, or written in numerical form is 1950. It sounds like you are overlooking the "mil" part, which is 1000, or you are trying to make the Spanish version be worded in exactly them way we say years. Duo has it right. It's not 1000 19 50. It's 1000 900 50, which is 1950.