The Princess chassis is identical to the Duchess / Coronation chassis. However this features the installation of a Loksound decoder in the tender, and a Sleuthe smoke unit. This loco is the ulitmate
For realistic running. This decoder can only be accommodated in the tender.

Make the tender a permanent connection for this I use a M3 cheese head screw and nut. Remove as always the the TV supressor and the Hornby tender connector. The plastic remains of the connector can be used to connect the tender to the loco. The speaker will fit above the decoder.
The decoder wires are sheathed in shrink tube to protect them and improve the appearance.

Not all the decoder wires are run through the enlarged hole in the chassis. Some wires are routed beneath the footplate and inside the loco. These are held in place by Black Silicone Sealant.