Ok, I will post over there and try and get some other pics but it is hard with all the rocks.
Do you have any other information about the fish from the previous owner? Age? How long is it now?
They will likely need a picture with the dorsal fin open as well. ID'ing fish, especially some catfish, is tough and the number of rays in the dorsal fin is one of the big numbers that is needed to at least exclude other similar looking species. Sometimes by excluding the others, you verify which species you have.
Also, the age is a BIG factor since pleco's will change dramatically from the time they are juvis to adults. Just look at all of the pictures on that one link that was already provided.
On the now-defunct PlecoFanatics.com, it took us nearly a year to help me ID what ended up being one of the few species called "common plecos", Liposarcus pardalis... but when it was a juvi, nobody knew for sure. In my case, I had adopted a severely overstocked 10G tank (with about 150G worth of fish in it) and this common pleco was only around 4" long after two years in that tank. Fortunately, it wasn't permanently stunted since I moved it to my 65G tank and 18 months later, it was 10" long and growing. I had to sell it since I didn't have room for a larger tank after Katrina. Now, in your case, you don't likely have a common pleco type pleco but you could have anything from a dwarf species to a BIG type species and anything in between. Since plecos grow from 3" to around 24", it's important to know. That's also why knowing the age and living condtions will help us/them know if this fish is young or old, close to normal size or severely stunted, etc.