There are two "main" style R4 compressors, the regular and the "lightweight", and then several variations (and manufacturers) within those two. There are at least two main clutch systems that we see, and many clock positions on these. There are many pulley designs as well, because the R4 was a workhorse, in its day, for many, many different vehicles. The clock position is relatively easy to reset by removing and reinstalling(rotating) the clutch relative to the body and yoke. What needs to be watched carefully is the yoke position, so that the internal oil channels are pointed DOWN. This is usually marked by an "X" on the yoke, which is UP.
See post #10 inthis thread and the whole discussion is worth perusing:
http://www.peachparts.com/shopforum/showthread.php?t=125511&highlight=oil+yoke