It is a normal situation - to not have fwkern.conf file. Usually administrators creates this file himself, for these additional kernel settings to survive a reboot, when they are required for sure. If there is no fwkern.conf file and admin doesn't know about any additional parameters, I would assume that they are not needed in this case. Because even in case of power outage they need to somehow restore these parameters.
And did they never reboot their gateways? It is not a good practice for Check Point gateways.
I think this is what you need, but I never used it myself in practice:
Creating a file with all the kernel parameters and their values
If the solution above is not working, or you want to make sure and verify, you can get a parameter value with fw ctl get int <parameter> command. But for that you need to know the exact name of a parameter. So you can try to find out if some of oftenly used parameters are changed, for example:
fw ctl get int fwha_mac_magic
fw ctl get int fwha_mac_forward_magic
fw ctl get int fwha_forw_packet_to_not_active
Here is a list of some other parameters - Kernel Global Parameters
And you can try to find some other ones on Support Center in different sk by searching "kernel parameters":
Dynamic NAT port allocation feature
ClusterXL - CCP packets and fwha_timer_cpha_res kernel parameter