You could use the Webassist->Preset Manager UI to export and import your settings. But if you want to copy files manually I think these will do it, but i may be missing some.
Form Builder: /Configuration/Shared/Webassist/FormBuilder/FormDefinitions
CSS Buttons: /Configuration/Shared/WebAssist/CSSMenuWriter/ButtonPresets
Data Assist:/Configuration/Shared/WebAssist/DataAssist/XML
Menu Writer: /Configuration/Shared/WebAssist/CSSMenuWriter/presets
CSS Sculptor: /Configuration/Shared/WebAssist/CSSSculptor/presets, /Configuration/Shared/WebAssist/CSSSculptor/v2_presets, /Configuration/Shared/WebAssist/CSSSculptor/designs, /Configuration/Shared/WebAssist/CSSSculptor/designtypes