Thanks everyone,
I guess this is where the plate should be? When I order the data card will it have the engine number on it? Is there anyway to know for sure what the engine number is without that plate on it? Also I got it started for the first time today!!
I've noticed in my internet travels that there isn't a whole lot (or I haven't found much) information about the M121 engine.
https://www.youtube.com/watch?v=fPMXfyyj_EU