Don't recall a way to straighten the drawer fronts - think you just need to ensure the frame is fully straight. Otherwise if it's a few mm's out, then there may be something stuck behind it? So try taking the drawer out to check that. Good luck!
Sorry - realise that this is probably too late for you. But incase it's helpful for anyone else... The internal sizes are approx 625mm wide x 280mm depth x 180mm height
They were the standard Ikea ones that were available when I bought the units (couple of years ago now). Unfortunately they've stopped selling those ones and now only do the cheaper individual legs style without the horizontal wood strip. I bought another unit recently for my vinyl and was disappointed with the look of the newer legs compared to the original.
