The strut you need is discontinued. However there was a long post some time ago using a different strut from Monroe that had the same specifications, we were able to fabricate a working rear strut complete with the correct mounting bracket that also had to be fabricated. Marck at East Coast Reatta had contacted Monroe and had a run of 500 #71966 struts made but that is also now sold out. He was selling them for $499.95 a pair plus freight.
I have one extra set of the fabricated rear struts available. My price is $375.00 with freight. Contact me if interested.