I wonder if these systems, or upgraded versions, are still around. All I know is that my unit, 6/56 ADA (motto - Night Hides Not) was deactivated during the 90s.
The four years that I spent at 6/56 were a wonderful experience. Platoon Leader (Chaprral and Vulcan), Maintenance Officer, Asst. S-3 (Operations Officer), Asst. S-4 (Supply Officer), and S-4, were the positions I served in. I arrived as a butterbar (2LT), and left as a Captain.
Culturally, it was a great experience, as I was able to live in Traben-Trarbach, a small town on the Mosel River, for 3 years.
Neither the Vulcan or Chap are in the US Army inventory (not even the National Guard). However, I was at North McGrager Range about 2 years ago and all the Chaps were there being refurbished for FMS. The only C/V you'll see are on display.
IT FLIES, IT DIES!!