From the mid 50's to the mid 60's the german model designation was the number cylinders first and the hp second.
In 1963 came the D-514 based on the 504 and the first digits the amound of hp. and the last digid the number of cilinders.
In the mid 60's most European models used this kind of designation. This started to end in the late 70's with the introduction of the 955, the first digids still telling the amound off hp, but the last digid doesnt represent the number cylinders.
Also the number designation can be different by country. The 845XL was build in France, but the same tractor was build as the 844XL in Germany. When de the production of the 844XL ended in Germany and was moved to the UK in the late 80's, the tractor was build as the 845XL, but for the German market still sold as the 844XL.
The UK build 85XL and 95XL series were sold in north America as the 85 and 95 series.
Also in Europe we had the Maxxum 5100-series, 5100 Plus series and the 5100 Pro series who were sold as the Maxxum 5200-series
The magnum 7200 Pro series were sold in the US as the Magnum 8900-series.