I might as well continue this adventure.
So after looking in the RPMS dir of the installer I ran:
[root@<blah> RPMS]# rpm -ivh opensm-libs-4.2.5.MLNX20140828.7f05469-0.1.x86_64.rpm
warning: opensm-libs-4.2.5.MLNX20140828.7f05469-0.1.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 6224c050: NOKEY
Preparing... ########################################### [100%]
1:opensm-libs ########################################### [100%]
Preparing... ########################################### [100%]
1:opensm-devel ########################################### [100%]
But this did not bring the joy I had hoped for:
error: Failed build dependencies:
opensm-devel is needed by ibutils-1.5.7.1-0.10.g385f871.x86_64
libibumad-devel is needed by ibutils-1.5.7.1-0.10.g385f871.x86_64
Installing /root/mellanox/MLNX_OFED_LINUX-2.3-2.0.0-rhel6.6-x86_64/src/MLNX_OFED_SRC-2.3-2.0.0/SRPMS/ibutils-1.5.7.1-0.10.g385f871.src.rpm
Everytime......