Beverage Air

[WDG]

Can anyone help identify what these plastic inserts are for.  They seem to do nothing.  These are just below the evaporator but the other side of the tub has a full row about 2" from the bottom and 6" from the top.  I think the holes were punched so the tub could be used for multiple purposes the same as the compressor plate has about 40 holes in it with most of them not being used.  I tried to pry one out but stopped when I thought it was going to break.  I need to sand the tub, prime, and paint it but with these inserts in the side I'm not sure if it's ok to take them out and try to find something to plug them back up with.  Any suggestions?

I have a couple more pictures.  I'm thinking of just leaving the plugs in and sand blasting then taking them out,( they will all break) and then trying to find something I can put back in after I paint the tub.  Has anyone seen these before?