Destroyed a build by rotating it?

I needed to rotate a build 22.5 degrees, so I had this brilliant idea that I'd select it all and rotate it. Trouble is, there's no way to know how much it is rotated. The rotation fields are for one piece withing the thing, and there doesn't seem to be any telling which piece it even is.

So, now I have the whole thing rotated to an unknown angle, and prim drift has ruined this copy.

Before I rotated I took a copy. When I place it out of inventory as far as I know it will be placed at an arbitrary angle. Is there a way to rotate it to a known angle?

Thanks,
Anna

More information: When I place it from inventory it is at the original rotation. I want to rotate the whole thing 22.5 degrees. Can I do that?

More information: 22.5 is one of the click-stops on the grid, but it rotates something other than 22.5.

I have an octagon with two opposing "points" aligned on the X-axis, and of course another two opposing points aligned on the Y-axis. After I rotate it 22.5 degrees the faces rather than the points should be aligned to the grid, no? It looks close, but for this object of about 26 meters, it gets off by about 0.3 meters. Need I say that's horrible?

Edit to add still more info: I get a different rotation every time I try this (the click-stop at 22.5 degrees). Sometimes it's so bad I can see it's not aligned without checking the numbers.

Link the build, if possible, to a prim that is rotated to all 0,0,0.
Then punch in the values instead of doing it by snapping on the rotating widget.
You can get rid of this reference prim later if you don't need it.

The values of a linked set relates to the root prim. If you use the widget, it rotates it about the center of mass, which is no good. So, keying in is better when accuracy is needed.

You can also point at one of the value boxes (X, Y or Z) and hit the up and down arrows to nudge it one degree at a time.

Cottonteil's suggestion is great if you're able to link the whole thing. If not, you might want to try one of the auto rezzing packages like Rez Foo or Builder's Buddy. I've never used them myself, so maybe someone can correct me if I'm wrong, but I'm pretty sure that after you package a build in one of those things, the orientation of the pieces becomes relative to the rezzer object, so if you rotate the rezzer, the build it unpacks will be identically rotated.

Here is how I solved this problem...

The build is too big to be linked, so I rezzed a fresh copy from inventory and created four link sets, being careful to select a centered piece as the last member of each set. If there weren't four centered pieces I could have added a centered piece to each link set, as was suggested above.

Then I just rotated each link set by typing "22.5" into the Z rotation box. As far as I can tell there are only 2 very minor rotation drifts to correct.

Thanks for the suggestions. I will investigate the building rezzers.

I had this problem often when I first started building until I realized the object rotates with the root prim being what you're actually rotating, with all the connected pieces following. Now I just make sure my root prim is 0,0,0 rotation and havn't had problems trying to get odd shaped objects to rotate properly.