The OSSA kickstart mechanism is basically a GasGas design.  There is no need to remove the kickstart lever to remove the clutch cover.  The photo below shows the very important alignment of the quadrant sliding gear, and preloading of the return spring before reinstalling the clutch cover.  When reinstalling, you must wind the kickstart return spring up slightly from its relaxed position prior to putting the clutch cover back on.  Take care with the thrust washer at the end of the kickstart shaft (not shown in the photo below).  It is easy for this to fall off during reassembly.  I grease this washer to help keep it in place, and I lean the bike to the right when installing the clutch cover. 

The loop in the assembly fits into a mating recess in the engine casting. 

There are a lot of GasGas parts that I think should work (or could be made to work) on the OSSA.   One example is their kickstart pedal kit,  GasGas P/N MT89000CT-CBN-1.

Lately, prior to removing the clutch cover, I have been using a zip tie to secure the kickstart pedal to the clutch hose.  This keeps all the internal parts in the correct orientation for easy reassembly.

Alignment showing preload of spring 

Parts order for reassembly

Sure looks similar.  GasGas kickstart pedal kit, P/N  MT89000CT-CBN-1