Can you advise what you are going to do with it and what your needs are? For example, I have @ 14 or more harnesses. Some barely make it around my wide ass any more. If you were doing something super cool, like taking a 78 year old woman up her first mountain climb (snow), I'd be temped to just give you an old POS that would work great for glacier travel at a time when a crevasse fall could only occur intentionally as they are so open and visible, but that might give the Todd Skinner effect if you jumped off the Leaning Tower.
Portland State rentals: https://www.pdx.edu/recreation/sites/www.pdx.edu.recreation/files/EQC%20large_0_0.pdf NO
REI, they use too rent such things: https://www.rei.com/stores/rentals.html#oregon Perhaps?
"Mountaineering Gear" should include Ice axes, crampons...harness's? hmmm Call them.
Oregon Mt Community, they use to be the go - to guys for this very thing. http://www.omcgear.com/rentals
Looks like you need to call them. Good folks, but I won't speak for my knowledge of 40 years back. You need to call. Phone: 1-800-538-3604
If any of that trash don't work, speak up and we can help you sort it out. Or die trying:-)