The osgmissionplay.exe file you have requested: Maps Levels Missions / MW4 OSG Mission Play Pack - 5.28mb is not available. Perhaps try browsing all files for the game Mechwarrior 4: Mercenaries and upload any files you want to share or are missing. This is the only information we could locate:
Additional Mission Play set on the Old Stomping Grounds terrains, previously released by AS Studios. Get the terrains here - Fileplanet.com Four more objective driven scenarios for MechWarrior 4 Mercenaries.