I just got some spotted BN pleco. The spots on the fins of yours are all over mine, but their bodies are a lighter colour than yours. Yours must have a gene somewhere way back for spotted.
Will try and get some pics of my 2 new BN's, but they've found a nice hiding place at the back of my tank under some rocks, and I never see them out !!
Fingers crossed they'll get more adventurous when they've settled in to the tank.... they've only been in the there since Sunday...
Its almost impossible for 'common bristlenoses' - I'm not sure about ours, it's only the fact that our females dont have bristles that points at the L181's...