I have the XTM, its the same as the FG Marder race version, has threaded alloy shocks and gear cover and a few other things.
The marder , Firehammer, XTM, Carson, and Spider are the same buggys.
I have a list of parts that fit, and there are more that are not on the list.
Look throught he forum and you will see they all are pretty much the same.
Have fun.
http://www.molzermoweryracing.com/firehammer.htm