Along with some other stuff we bought two used trains, a Hornby Class 37 and an old Hornby B12/3

The class 37 wasn't working so I cleaned the ringfield motor and it now runs like a dream, I don't think I'll pull the motor out and replace it like I did with my 125.
The B12/3 is a different story, it kind of worked but way very noisy. I've taken the engine apart (x03 I think) and cleaned it but the brushes are very worn, I couldn't find the oil seal things either. I've bought the brushes, seals and a new magnet. Is there anything else I should think about for that engine?