That's about right, I'd say. My last batch I used one ounce of magnum to provide the bittering, then all cascade. According to the software, about 39 ibus. And I used Safale 04. You might want to reconsider using a whole pound of crystal. Might end up a bit sweet. I actually use Munich in mine instead of C20.
"Beer, well respected and rightly consumed, can be a gift of God. It is one of his mysteries, which it was his delight to conceal and the glory of kings to search out."
The Search for God and Guinness by Stephen Mansfield