Lucky find today from an expired eBay listing, quality pictures of Fluke AC-09 True RMS AC Option Card.
Many owners of used meters they wish having one because this it would increase winning bid on eBay, from the other hand True RMS measuring technology this changed allot than how it was calculated in 1980 at limited bandwidth.
In the negative side of things, if you do have Fluke AC-09 True RMS AC Option Card and this is damaged, then it must be removed so 8840A to recover / regain functionality.
Within 2018 I did succeed to repair two of such option cards fitted in two 8840A dmm.