Got this long ago, not sure if it was from MWO.
The main pillars top pieces can move up and down
Bottom claws can rotate
Bottom arms can extend in and out
Bottom claws can swivel
Top claws can swivel
Top arm can move in and out
Back brace can move in and out
You can use filament or tooth picks for the joints. I left holes where you can stick it into.
Hopefully this will allow for any mech size to be placed in the harass.