Thanks for both your replies.

I am pretty convinced that Plec 2 (the first pic) is an L66. They were sold to me as L260, Queen Arabesque which they are clearly not, markings were very faint when originally purchased. I think Plec 1 may be different, and it's interesting comparing against the L401 ...

I have 2 of these Pleco's in my aquarium and cannot decide which exact L number they are, I have narrowed it down to an L66 or an L333.
I would greatly appreciate any help in proper identification of these fish.
I have tried to get good pics of them side on, if required i could get different pics ...