I'm rebuilding my bed in my 1952 1300. I don't have a lot of money for this so I'm just using fir planking for now.
When I was drilling and installing the carriage bolts I was having a heck of a time trying to get the washer on the bolt before the nut in the limited space in the support rails.
I ended up using a big magnet on the top of the bolt then the washer would stay on the bolt while I put the nut on.
Hope this helps somebody as it sure made the job more enjoyable.