The JCC come in at least 3 flavours of box, the piston is common to all, rings can be either not supplied or supplied and one of several options depending on seller. They come as Craft Cycle which is the JCC own brand, LFH and the current Wassell Hepolites. Nural look to be part of Federal Mogul who bought the Hepolite factory but cannot use the Hepolite brand as they have licensed it to Wassell for motorcycle pistons, believe the factory is based in South Africa, the wonders of global suppliers.
Wassell own the Hepolite brand, trademarks and associated goodwill etc, purchased from Federal Mogul. As John states, JCC supply in their own brand, and to other re-sellers, including CycleCraft, Emgo, Harris etc.
The Nural pistons are still available via Federal Mogul, and have historically been reliable.
As Hawaiian Tiger suggests, rings is another subject altogether, although there are actually very few manufacturers out there.