157 is a pretty high mash temp for easily fermentable sugars. Also the crystal malts aren't going to be as good at producing easily fermentable sugars like your base malt does. I also think WLP001 has a tough time doing hard work at 62.
My opinion is that 1.020 might be all you're gonna get. I bet it still tastes good.
On Tap: Mt Hood Kolsch, Little River IPA
Primary: Little River IPA
On Deck: Little River Brown Ale , Sour Brown, October Alt