I’ve made flip top tables before but used no pins or bolts to pivot on. My plan simply lifts the top off the table frame and is turned over by hand. On each side, put 4 blocks at each corner to fit snugly inside each corner of the stand. When the planer side is flipped down, the 4 blocks hold the scrollsaw in position. When reversed, the planer is up.
These 4 blocks are below and out of the way of each of the tool tables.
If you don't have time to do it right the first time, when will you have time to do it over?