Thanks for asking : ). These tiles were created at a base size of 32x32 so to get them to 48x48 for MV would stretch them out in unpleasant ways. Unfortunately they are not compatible with MV.
Don't mean to necro this thread, but I have scaled them manually in photoshop and they look fine! Just need adjust them slightly, but yeah you can do it! Take the original RPG maker tilesheets you include for the older version, and you can do a sheet inn about 20 mins