I picked up the wingspar 6-W-3-R, and start deburr ribs 6-W-5-53, -2, -52 and -51. Add primer on surfaces where ribs and spar meet. After drying, mounted them with clecos. The inboard 4 ribs expect to be mounted between two angles, but only 2 are mounted. I found 5 sets of 6-W-11-52 angles in the kit, seems to fit together with 6-W-5-52R. But no information in manual. Have to send a question to ULM again.