I saw these for sale at greatbreweh.com, researched and found they are a small pump designed for use in solar hot water heaters. Pump body and impeller are Ryton, with brass inlet/outlet. They are made to run off a solar PV so they work on a range of DC voltages. I bought a Pumpsflo 15 that is supposed to pump 3gal/min. I am wanting to use it for whirlpooling with an IC, so I plumbed it up for this and gave it a run tonight. Heated water in my kettle while running this little pump, went to 97F and measured flow. It was 2gal/min, enough for a nice whirlpool from what i could tell. Primed itself nicely although I didn't start it when the water was already hot.
I bought this for $61 from ebay (free shipping), the ones from the site mentioned above are about $84 with shipping ($70 apiece if you buy two) and they come with an AC converter and the brass is mostly coated with Ryton. If I build a brew stand I'll probably buy a March but these things are a nice alternative. Its less than half the price and has less than half the flow, seems fair.