Hi folks
Interesting info but I have 3 axel bogies with no underneath screw fitting. The coupling is linked internally to the bogie and hence turns on courners.
The coupling is in a ,box, which is thicker on one. There appears no way to remove this. To dismantle the whole body to get internal access seems somewhat difficult without causing damage.

Can anybody help. Some years ago whilst in Florida I purchased a loco and four Norfolk and Western spectrum coaches. On return to the UK I decided to purchase an observation car and baggage car. However the coupling height on the later two have a slightly different height. There no loose parts but the construction is slightly different. Strangely the observation end mates the original coaches.
Does anyone have a useful suggestion.
Many thanks.