Keyboard open display moveable plinths

The At Home with Music display in the Music Gallery features domestic keyboard instruments from a period of 500 years. Three instruments currently on display will be removed to allow three recently-acquired instruments to be installed in their places. Each of the keyboard instruments will be in playing order and will be used on a regular basis, therefore each of the plinths for the 'new' instruments must be capable of being used both in place AND withdrawn from its display space and wheeled to another potential performance space. The plinths that carry the instruments must be of a dimension that enables them to be wheeled through the doorway into the Music Gallery Performance Space, an area immediately adjacent to the Gallery but separated from it by a glass door. A fourth plinth will be required which can be wheeled and locked into place in front of the new plinths so that a performer can be comfortably seated to play each of the instruments. This arrangement demands that all four of the new plinths be of the same height. The new plinths, since they will fit into an existing display, must closely resemble in visual style the original plinths and those that remain.