That very well could be a neutral yeast strain that is just used for bottle conditioning, hard to tell. Imperial has the Elysian strain, but it is very rarely available to homebrewers. The strain is A30 Corporate.
Pretty sure you have two 525s and two 425s. 500 or 600 series is a whole body, while the 425s have the removable spout and have the whole shuttle assembly inside the body instead of the ball/o-ring seal. 425s are rare these days.
Here is a smattering of ismellweird threads, good stuff really:
https://www.homebrewtalk.com/threads/from-a-porch-comes-a-barrel.649043/
https://www.homebrewtalk.com/threads/who-is-this-guy-i-was-talking-to.638409/
https://www.homebrewtalk.com/threads/need-help-locating-a-movie.648384/...