This RSX plugin will in install a button and the exporter to import and export PSA and PSK models to and from Truespace 7.6x workside. To install it hit File>open>RSOBJ. Then open the Link Editor and left click the installer.
To access the PSK/PSA dialog right drag click the right side of the TS workspace wall and drag it left to expose the dialog settings window. If you have the TS bridge activated then you can use either the workspace or modelside to edit your Unreal models. I highly recommend Truespace for model making as it is a very easy to use model creation tool. The hardest part of using Truespace is spending some well spent time learning the TS user interface; it's all icon based as far as the modeling tools are concerned.
Start by clicking the Truespace 6 tab; this is the original Caligari user interface and it will help you get use to how TS interacts with the model maker. Each icon does some function in TS. Icons are arranged in TS in the form of Menu Bars; most are minimized in tiny little box icons that when left clicked expand again and if you left click them again they will expand to the full view of the menu bar itself. This is the prefered view in TS to make using the modeling tools more efficient for most new model makers. It's also one way to get things done more quickly as all of the tools are clearly visible and accessible; you can always minimize them later if you prefer.
Once you get used to the old user interface then you'll be more comfortable when you start using new workspace side of Truespace; it too uses a simplified set of icons only these are not fully expandable. To expose the other hidden icons in the menu bars you left click hold and move the mouse cursor to view them and let go of the left mouse button when you find the icon tool you want to use; personally, I prefer the old UI as to me it's more efficient. I also prefer the old Caligari modelside modeling tools as well.
Another tip I suggest is learning to right click icons as this is the way to adjust tool settings in the modeling tools; this is also used to enter the Object Editing Mode in Truespace. Once you begin adding objects in to model work space right clicking any object activates and exposes the object editing controls in yet another menu bar; it's a very effiecient way to quickly modify object in TS.
Don't let the icons overwlem you as once you get to use to basic concepts behind them you're going to love how fast things can get done in TS. I leave my menu bars fully expanded most of the time and use the Truespace 6 modelside extensively. I use the workspace side to work with newer model formats like those supported by the above listed PSA PSK Rsx based plugins. Have fun, Leroy aka BNG123!