If all you need is a replacement bolt, we have you covered. All Stainless Steel Hardware comes as a set of 2. May require enlarging of holes on older boats.
 (free shipping)
Seat
# 6 x 1 ½" 
# 6 Lock Nut
# Finish Washer
Thwart 
# 8 x 1 ½"
# 8 Lock Nut
# Finish Washer
​Backrest 
# 8 x 2"
# 8 Lock Nut
# Finish Washer
# 8 Wing Nut
Yoke
# 8 x 2"
# 8 Lock Nut
# Finish Washer
# 8 Wing Nut