What I had initially intended to complete for the FSX Biff is now complete. There was a delay of a couple of days due to code for the fuel selector switch not doing as I wanted. This morning I dropped the approach used by MS for their fuel selectors in FS2004/FSX and coded my own from scratch. It does what I want when I want.
Presently I am doing a few skins and minor visual variations. So hang on it may take a couple of days more :)