A customer replaceable unit (CRU) assembly for mounting in a sheet handling machine is disclosed and includes (a) a CRU frame having a frame size for fitting into a mounting portion within the sheet handling machine; (b) a first roller assembled rotatably to the CRU frame; (c) a second roller assembled rotatably to the CRU frame and for resilient contact with the first roller to form a sheet handling nip; and (d) a spacer and anti-mounting assembly including (i) a holding feature formed in the CRU frame and (ii) a removable member mounted in the holding feature for temporarily preventing mounting of the CRU frame into the mounting portion within the sheet handling machine, and for temporarily spacing the second roller out of resilient contact with the first roller so as to prevent roller flat spots, operating roller noise, and premature roller failure.