From 26th to 30th December 2013 District Line track works resulted in buses replacing Richmond & Wimbledon trains and Piccadilly Line trains replacing Ealing Broadway trains.

Between Hammersmith and Acton Town stations *most* Piccadilly Line 1973 Tube stock trains travelled on District Line tracks and called at all stations.
You drive a Piccadilly Line train from Hammersmith to Ealing Broadway then back to Ealing Common Depot
This Scenario has also been uploaded onto the UKTS Download Forums
https://www.uktrainsim.com/filelib-info.php?form_fileid=36794
Requirements: Virtual District Line Available here http://lur.boards.net/
That is all you need ?