The Schlage Latitude levers can't be used with Von Duprin 98/99 series exit devices.
The L Series lock can fit into a door prepped for the SCHLAGE K Series with some additional prep as described here.  
K and L trim and parts are not interchangeable. 
Indicator not extended Indicator extended
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 pr...
Frascio is a company that provides decorative lever sets for many of Allegion products.  More information can be found on their web site at WWW.frasciointernational.com.
Schlage offers Falcon Retrofit cylinders to fit many of Falcon's locks.  Table 1 below contains part number for T series locks.  Table 1 - Falcon retrofit cylinders  
Key in lever Falcon cylinders do not work in Schlage locks.  The cylinders may fit, but there are no specific tailpieces created to operate any Schlage lock. SFIC SFIC is universal so Falcon and...
   Hotel cylinder in L9000 As long as the correct cam is used (Schlage clover), a Falcon Hotel cylinder will properly function in an L9486 hotel lock.
Falcon D series deadbolts will not accept Schlage Key-in-lever cylinders. The faceplate plug hole is smaller in diameter than the Schlage plug and does not fit flush when i...
For a Schlage "C"  keyway:  Specify "CP6" as the cylinder suffix when ordering  D100 or D200 locks (All other Schlage keyways are not available).
The Schlage AD/CO trims are not compatible with the Falcon 25-V device due to the main cam on the device rotating the opposite direction for a given hand compared to the AD/CO trims output dri...
The RU lock can accept a Schlage Full Size core, but the cylinder suffix must be specified as "J IC-SC" so the correct parts are supplied. The tailpiece will come with the lock. Example: RU581J IC-SC
The following application information apply to the 5100 electric strike: Can only be used on a single door with a cylindrical lock Can not be used on a pair of doors Can not be used on a mullion