On my 1939 3/4 Stake the sideboards were southern yellow pine and the picket/uprights were oak. The bed was also southern yellow pine. Carriage bolts were used on the side boards with T-nuts. The T-nuts had 3 notches in them to turn them tight on the carriage bolts. The corner, steel window behind the cab and panel hardware was carriage bolts with square nuts. Drop me a PM and I'll send you samples. I fashioned a 3/8 drive socket into 3-prongs to turn the T-nuts.
Rick
