It looks like its taped in Russ but not to sure how, maybe a plate thats screwed down!! the tape goes in the wrong direction to be through the battery slots!
I've got a lipo saddle here mate if you want to see how it might fit. Biggest problem i've had is with the connectors and wires sticking up to high

and stopping the shell fitting correctly.
But the test out in the street has proven it to be awesome