That is a whole inside round (top round) with the fat cap removed.
A friend of mine and I started a little BBQ business on the side back in the 70's. We got a haywagon, cut off the top of a propane tank, cut it in half lengthwise and welded the two halves together, added feet, then added angle-iron uprights with notches in them on each end. 'Acquired' a stainless steel 1" rod about 10' long and welded a small gear on one end. Added a couple prongs with connecting bars and would string up 4 or 5 whole inside rounds on the contraption, with the connecting bars keeping them all rotating in unison. We used slab wood from the nearby mill (outer wood cut off the logs, real cheap) for the fire in the pit, then would hoist the bar up onto the upright notches about 4' off the coals and hook a small gear motor via a small chain to the bar. The center weight of the meat caused the end to rise up, tightening the chain on the gear motor (which we clamped to the upright with vise grips) and would slowly turn the spit round and round. We'd start at 7 am and by 2 pm the rounds would be at 130°. We'd chunk them off and throw on the slicer (I used one from work) and slice off thin and serve on a wick with horseradish sauce and au jus we'd cook on the side. OMG was it ever good! We did private parties only for the mill execs. Unfortunately the State got involved and forced us to shut down because, of all things, they wanted a 'sneeze guard' mounted over it, plexiglass. Which of course would have melted. A tin metal roof wouldn't have worked, had to be a plexiglass sneeze guard. But, regardless, it was a great sight to see all that meat going round and round; people would mill around watching and chatting, drinking beer and talking while their heads would be absently circling around in unison!
My friend owned an RV park so he took it up there, built a screened in gazebo and permanently mounted it to the ground and would do cooks for the guests there on it, either spitting or grilling. But every time I see a whole inside round I remember the fun we had with that home built rig!
Sorry to hijack the thread with my storytelling! Back to the Italian Beef! It looks wonderful!