Removing Bed from 66' GMC

[bbluma]

Hey yall, so im trying to remove my bed to swap with a better one that i have found. Well the people before got weld happy and i believe just welded a bar onto the arch part that the bed sits on like in the photo.

From what i know the bed is suppose to mount through the hole (in green) to the frame. the white circles are welds, and i have no idea what the orange bolt is too. i think its part of the random bar they put in because it doesnt look like a cross sill. So should i just undo the bolt and cut those welds and call it good? or am i just completely wrong and missing something? Thanks.