Factory tool box??

[starfire58]

Hey guys- I just purchased a nice rustfree 8 foot box for my 71. The right box side has what appears to be a factory toolbox built in to the lower front. the sheetmetal is actually stamped with a recessed lip that has a fiberglass box that extends in and is attached to the bed floor with brackets on the top of the rear of the toolbox. the door on the outside fits flush and has a piece of lower woodgrain trim acroos it. there is also a door lock cylinder on this door. I've never seen one of these. Are these common? I almost passed up this box because of the toolbox. I dont really like it but I do have a perfect rust free box side I can change this one out with. I just wondered if any of you have these in your beds or is this somewhat uncommon or rare? Just curious.