Shout-out to Raritan Engineering. I accidentally cracked the porcelain bowl of the head that was original equipment in my 1974 sailboat, and needed a new one. Not only is the company still in business, the parts from a model they still sell are compatible, 50 years later! Their support techs were able to tell me exactly what parts I needed to buy.

Actually, quite a few marine brands are always reliable. The harsh environment at sea tends to out cheap crap in a hurry.