In November I found a Mini club 50th anniversary set 81873 in a shop in Vienna, this contains a Cl216 Diesel and 3 express coaches (plus track and a controller) contained in a repro woodgrain carton. Naturally I bought it.
Last week I found an original 8901 set containing the Cl 216 and 3 coaches (track but no controller) for sale so bought it to complement the other set. The date on the box is 8/72.
The vendor said that the loco lights worked but would need some running after standing.
The lights did indeed work but the loco wasn’t going anywhere! The pin securing one of the bogies was seized solid but after extracting and cleaning it and applying some Teflon lubricant to both bogies the loco worked - rather reluctantly and kept tripping the Rokuhan controller I was using. So, out came the motor to lube the armature bearings, this necessitates removing the circuit board and the carbon brushes. On reassembly I was back to square one - the lights worked but no movement. I retensioned the spring contacts under the circuit board but still no movement. The brushes were equally worn suggesting the tension was ok, swapping them over produced a result though. This loco is the best performing 3 pole I have now, goes like a rocket with no excessive heating.

Why swapping the brushes around should make a difference I don’t know.
ChriG