I knew this was going to be tough, so here is another reference, the E in WE on obverse, when turned over aligns with the E in CENT, normally the C. My guess is 45 degrees.
Put it in a 2x2 with the obverse aligned really well, take an image from directly overhead, flip it and do the same. I can tell you the degree of rotation with the editing feature on my iPhone. That is how I do mine. The best I've found is 18 degrees & it looks like way more. It's tricky on the eyes with something that small. I thought mine was for sure 30 degrees or better. Turned out 18. Edit: This would be 45 degrees. It's a lot.
Rotation did not exceed your specifications for exceptional. Thanks for the help. With the base of the memorial below the diameter of the coin, the rotation seemed greater.