Speed Runner lets you adjust the core and memory clocks to overclock the card, however in this case it appears to be sorely outdated. The max core clock setting is only 600Mhz, far below the card's stock speed of 738Mhz.
I wasn't able to overclock using the nVidia Performance utility either. Like GPU-Z it would not detect the clock speed and simply showed 0Mhz.
I then loaded up Riva Tuner, which is my usual software for controlling GPU clocks.
Unfortunately it couldn't help me either. It did not detect the current clocks, even with a reboot.
Thinking that it may be the Leadtek supplied driver I downloaded the latest WHQL 180.48 driver and installed that. However I continued to have the same problems with GPU-Z, nVidia Control Panel and Riva Tuner.
Resigned to not being able to overclock this card, let's move on to some stock benchmarks.