The replacement for the D871 is the D271. None of the parts are backwards compatible.
D271 description:Thumbturn x Occupancy Indicator
Deadbolt thrown or retracted by turn unit only. ...
The Falcon D400 and D800 series (including the D871) were discontinued in 2008.
The indicator on a cylindrical hotel lock is a small pin that projects outward from the face of the cylinder plug (Figure 1) when the inside push button is depressed. When this pin is ...