As you may mentioned already, R75.10 is recently released.
There were some hopes on the field that this release would unblock some dead end upgrade paths for versions such as R65.4 and R71.30.
That did not happen. There is no direct upgrade to R75.10 from any version bellow R75. You can check out the updated upgrade diagram from fileserve.org here.
It means that someone having R65.4 is still blocked.
This is quite painful considering R65 is out of support for some time now. Check Point, what's going on?