Keep just one specific kernel version

I ran into a situation where we needed to boot into rescue mode to 
repair an older F7 system.  Once in rescue mode I chrooted into 
/mnt/sysimage and tried starting rpcbind and nfs.  I was greeted with 
errors about couldn't find kernel lib modules.  Then it dawned on me 
that this system had been updating the kernel so it no longer had the 
original kernel available that would match the kernel from the rescue 
disk. 

So is there a way to keep the original kernel and still allow the system 
to update to newer kernels?  I just want to keep the one original kernel 
version so that it will match rescue mode.  Otherwise the system should 
be free to update the kernel if it wishes and only keep two most recent 
kernels (plus the one original kernel).


Regards,
Gerry