Do have the rudder and all the pieces to install one on the Riot Brittany 16.5 kayak?

Yes we do have the rudder kit for the Brittany 16.5 that includes all the parts and hardware you need.

https://boutiqueborealdesign.com/products/replacement-small-rudder-kit-for-brittanyincludes-rudder-c-bracket-rudder-support-rope-v-block-hardware

The only thing I don't have are good instructions for installation but if you are good with repairs, then should be ok to do yourself OR take it to a marine or kayak dealer that does repairs like this.

Thanks.