Bob:
For what it’s worth, on my ’87XL, 102″ wide, the rear bumper center section is 74″. It has rather long corner pieces, with 2 small holes in the end which wraps around the side of the bus, as well as whatever bolts them on and to the center section. I should have taken pix.
The front bumper, center section, is longer: 82-3/4″, with shorter corner pieces with no holes other than for 2 carriage bolts which attach them to the center section.
Due to the difference in years, yours is probably waaaay different. Good luck.
Ted.
1999 XLV X-6872, liberty #440