Furlough day three. Cleco'd the reinforcement plates and platenuts to the spar. Used the C-frame back riveting technique to set the upper two plates. All rivets set well. Assembled the R-904 rib, rudder horn, spacer and reinforcement plate with cleco's and began riveting with the gun and bucking bar. All rivets went well here also. Riveted the R-710 brace to the rib, will use blind rivets for the 710 to 405.