That is not a part. It is a piece of scrap.

Part #32, the hatch cover support is the rectangular piece that was removed from the center of that piece.

That piece was removed from a larger part to create a "lightening hole". This would normally just be scrap, but that piece of scrap was large enough to have another part punched into it, so in order to save wood, that's what they did.

The reason the "32" was stamped on it was to prevent stamping it into such a small piece.

Bottom line, you don't need it. Save it as scrap for another project.