You used a solid bar for the hitch? Way overkill.
I may be wrong (but I doubt it!), but judging by the tag on the bar, mostly hidden by the receiver, as well as having seen a LOT of them, when I was getting ready to build mine (never did build it, but got "real ready"!), I would say it was "store-bought" exactly like that. Every single one I have seen, in any store, has been solid. At least, the smaller 1-1/4" ones. I did find some that weren't solid, by googling, but think solid is pretty much the norm. I would also venture a guess, that the receiver tube itself was store-bought, as well, since it has the "collar" around the end.
Again, I could be blowing smoke...
R
The one I have is store bought & solid.... Just like the one in the pic.