Why do you suspect that the engine on the pallet is different to the one in the rebuild, I can't see anything noticeable but might be able to once it is pointed out
Look at the two rectangular silver plates just under where the intake manifold sits on the pics of your engine, they are called tappet chest covers and are only found on 998 A+ engines, not 1275. Now look at the block behind the carbs in those engine build pics, no tappet chests. They are different blocks, one 998 the other 1275















