well you can always go to heritage coin .com and join and search the archives. I don't believe this is an S/S error though. Need better lighting in your photo. Good luck though.
Playing with PAINT.NET to see S over S... I played with some pictures and will try to show what I mean...
I don't have a good camera I use a kids toy computer microscope to take my coin pictures. Google Digital Blue Microscope to see what I mean...I have the QX3+ version, which is older. It can do 10X, 60X, and 200X magnification...the pictures I posted were 60X. I'll try to take a 200X picture tonight, but the quality is usually low due to lighting.
You can find more information at CONECA: http://hermes.csd.net/~coneca/ They are an organization of error and variety specialists. The 1954 S/S varieties in particular are here: http://www.conecaonline.org/content/jeffersonrpms19461984.html#_1954-S You can also purchase a "Cherrypicker's" book.
Here's a photo of what a RPM would look like, I didn't see anything listed that described a tilted rpm as you are describing;
Close-up picture Here's a close-up picture (200X on the Digital Blue computer microscope). Sorry, it's the best I can get.
gouge marks It appears to me that there are 3 gouge marks on the areas where the tilted S appears, as if someone tried to eliminate the lower S on the hub with some tool. I could be way off base here though.