Oddly, the service manual don't give a torque value for the brake plate anchor nut or the large Hex Jam nut.
The large Castle nut that the cotter pin is supposed to be torqued to 70 N/M (52 ft/lbs). That is a lot of torque.
The anchor nut that is ahead of the axle and holds the brake backing plate to the swing arm is a 12mm nut so a conservative torque value would be about 20-25 ft/lbs
The hex jam nut that goes between the castle nut and the swing arm could have a high torque if it was made of good steel but because it is a lock nut with reduced thickness I suggest keeping the torque to around 35-40 ft/lbs.
All of these values over 35 ft/lbs are probably tighter than a person using a open end wrench (spanner) would want to use so the two nuts on the axle should be tightened up "good and tight".