Yeah, definitely looks like the scope and mount are based on the Han ANH, but the pistol itself is a mystery without better shots. It does look kinda like a Pulce, like y'all have said.
Also, the chrome Lando blaster was a custom job, not made from a real Rexim, for whatever that's worth. The real Rexim-based blasters are much prettier, in my opinion.
And Glocks WERE used for those silly looking Disney Trilogy blasters (Stormtrooper/First Order pistols).
EDIT: I looked at the scene in 4K, and I'll admit I didn't study HARD at the frames, but I paused at one point where he shoots someone behind him, and it does look like one of the Glock based blasters, just with a Han style scope on it...