Are you trying to convert Hornby Ringfield tender drive units to DCC?. (Motor is showing an example of where the screws can be used, in this sale you are purchasing the screws only. They are not suitable for Silver Seal Brass face plated models.).
Peters Spares PS13 Nylon Screws For Hornby Ringfield DCC Conversions Pack Of 10
Peters Spares PS135 X04 Motor Upgrade 3 Pole
Peters Spares PS136 X03 Motor Upgrade 3 Pole
Peters Spares (Peco PL-21) 4 Pole Double Throw Toggle Switch