Perhaps Pure can confirm some of my information then - here's what I have so far.
Looks like the spelling on that photo I found might have been wrong - I'm getting a lot more hits for "Pterygoplichthys joselimaianus", with lots of photos that match mine. The species name seems to be tagged 'Weber, 1991' consistently.
Common names include Gold Spot Pleco, L001 / L022, or Marbled Sailfin Pleco. The majority of the references I'm finding indicate it'll get up to about 12". I've been trying to find the differences between L001 and L022, but I'm not having much luck - something to do with the patterns. Amusingly, PlanetCatfish.com has a photo gallery that shows all the Lxxx designations with photos - it uses the same photo for L001 and L022.
Thank you for the tip Dino, it put me in the right direction.
Oh yeah - 1000 liters is probably extreme - I'm finding other references suggesting a minimum tank size of about 200 liters, four feet long.
Edit: 1000+ liters is probably the recommended size tank if you want any hope of breeding them - to quote the info from PlanetCatfish.com:
"Although commercially farmed, spawning in a home aquarium would be very difficult to achieve as a large wall of mud (I.E. a river bank) is tunnelled into and used for the incubation / hatching process. Large tunnels and fish would be required in a super-size aquarium."