I try not to go into my shop when I am mentally tired, I like my fingers. I've been pushing to finish a project and screwed up a dimension and I am well downstream at this point.

I have drawer boxes that are too large for the opening. I forgot to deduct the clearance for the guides on some of them. The box fits in the opening, but does not work with the under mount guides it hits the angle on the steel on the side of the guide. I can take a little material off each side on the outside of the of the box so it will clear. They are 5/8" now so I have it to give up on the outside, but my fit for the under mount guides will be off, they will not ride against the side underneath the box. Is there someone way to make this works properly without scrapping everything and starting over? I suppose I could cut a spacer and glue this into the bottom against the side?

Just a piece for my wife and I to use so perfection is not required

Thanks.

Brian