I ordered this cutting board from Amazon:
https://www.amazon.com/dp/B00HQN36XC/ref=cm_sw_r_cp_apa_i_cW4mFbQ3TN4AV
I also used folding brackets similar to these but bought them at my go-to local smoker supply store:
https://www.amazon.com/dp/B07VB77TBT/ref=cm_sw_r_cp_apa_i_nY4mFbTQVWSMD
The screws that are used to hold the original front shelf on are slightly larger than the holes in the brackets. So you will need to ream the existing holes up just slightly to about 1/4".
The smokers lower shelf holes did not line up with the bracket holes for me, so I screwed in the upper screws snug, but still loose enough to allow me to move the bracket to the side slightly to mark where to drill. Take the brackets off and vice em up. Drill the lower holes to 1/4” then screw them into the smoker tight.
Set cutting board on top and line up the corner closest to the smoker one either side and use 1/2" long or less wood screws to attach it to the bracket from below. On that same side, pull the bracket so it lines up with the edge of the board and install the next screw.
Repeat step 3 for the opposite side.
Fold down, then up, then down.
Enjoy!