Help unlatch my Sears chest

I have a red traditional Sears chest on chest tool unit. I have had all the drawers pulled out fairly recently.
After moving, I am unable to free up the drawers in the lower unit, even though the panel at the bottom is tipped up and pushed back which I think is supposed to release them. They are not locked with the key. The drawers on the upper unit unlock and are free when the lid at the very top is raised completely and lock when it is lowered and I can get into them. 
Can you help me get the drawers in the bottom section freed up so they pull out, where is the catch mechanism?

I’m guessing it’s like this one…


from here https://www.youtube.com/watch?v=PBCdzK_zlzc