Anyone ever heard of the Pereya Attack?


The difference is slight in that unlike a pure London, c3 is occupied by a pawn, the opening has few structural

What?
This is the mainest main line of the London. 5. c3 is the main move. Nothing you've said thus far is distinguishing the "Pereya attack" from just your standard London -

After looking at Pereyas games the only interesting thing he sometimes does is instead of c3 he'll play Ne5 very early on. So I'm guessing that's what you actually mean by the "Pereya attack". It's not an officially named line so... if you don't specify what you're actually talking about nobody is going to have any idea.
Manuel Miguel Pereyra Puebla vs Fritz Baumbach (1983)
As for my thoughts on it - well, anything is better than a typical boring London. I would play that over the mainline London every day of the week. I'd need a more comprehensive look at how he's playing other lines before giving much more of my opinion. But at least in that line it looks very similar to a Jobava but without Nc3. Eval is roughly in the same ballpark.