My recollection of table play in the 70's was that fills were always done with wooden racks. I don't recall how they were stacked in the cage, but I would think the same way. The wood racks really get beat up after a few years and all the edges get rounded. I don't remember there were fancy carriers to protect the "fill" as it moved from cage to tables either.

I guess these days it's cheaper to mold plastic than it is to cut down a tree and mill the wood.

I'd like to find a few more in any case.