An added note to Jamie's reply...
Thor has discontinued the Dutchmen line .. therefore, there may be no available records for the age of your tt (one would think they would archive important information)
Secondly, when we were speaking with Thor Warranty recently, 'Bob' pulled up our 'build sheet' from our VIN ... which he said showed every part and piece used in the build of our motorhome.
Rons thought is...if you can determine who manufactured the part/piece you are looking for you might be able to go directly to that company or supplier.
I will be happy to help out if you can give me a good description of what you are looking for.
I GOOGLED TWIST CLAMP... do not know if this is what you are looking for ...
try AMAZON in search window type Twist Clamp
they have several options.