Help with flow

Hello.

I’m new to GNU Radio. I have a Radio trace with the communication of two
devices. I know that one of them uses DBPSK and another 2-FSK
modulations. Both of them uses NRZI encoding. I attached my flow graph
in GNU Radio. Have I done it right? Actually, I absolutely don’t know
how to set up 2-FSK demodulation using FM demod block, however, I know
that it is possible.
I’ll be appreciate for any help.