Sweet! You got that "new" model with roller bearings. Mine had wood blocks filled with grease for bearings.But, alas, after the rebuild, mine now has nice roller bearings. If done properly, that break can be welded back no problem. It really wasn't all that difficult to weld cast steel, but it does take a particular process with a specific rod. Good luck! You'll have a nice piece that your grandkids will be using.
Why are the outside wheels on each end split? Is that so you can remove them easier and then slide everything around?
I'm guessing you are supposed to get in there and grease everything up before you use it.