Since no one still hasn't answered I will. It says in the description that it covers 1800 layout, so you can pretty much assume that it will fit fc980m perfectly. But it never hurts to double-check that yourself. Let's see:
Delete and PgDn keys for R1 row, check
Split right shift, check
1u wide 0 key for the numpad, check
1u wide alt and ctrl keys, check
Regular 6.25u spacebar, check
Missing: 1u windows key and 1.25u fn key, but I think that you're supposed to use #! novelty keycaps for those.
Everything else seem to be standard.
Edit: I really recommend Leopold fc980m if you still haven't pulled trigger on that. Especially if you buy the newer PD version (stands for pbt doubleshot). Though you might not want to use those pesky GMK caps after using the originals.