I built a few Kyosho legendary series kit, and one step is always difficult. Last time, I did not thought about this, but it's always hard to put the shock gaskets in place, and sometimes you break one.
This is my own attempt to solve the problem. This is small part designed to push the gasket in place.
There is two stl in this publication:

• the version for Scorpion 2014, Beetle and Tomahawk kits. The file name starts by SBT
• the version for Turbo Scorpion, Ultima and Optima series, The file name starts by TSco-Optimas

The way it works : position the gasket in the printed part, and simply push the shock part in...

Takes few minutes to print, no supports required and PLA is fine for this. Push it a few times in the shock part without gasket to make sure it is fine before trying with the gasket as this is designed to be a tight fit.