OK; lets start from scratch - I'm assuming nothing since its an after market joint. How long is the part of the joint that goes into the bearing (the skinny part; splines, threads, and everything)? That should be 4.25 inches. Next, when the joint is in the bearing as far as it will go; how much threaded part sticks out? That should be about 1.25 inches. If those measurements are OK; then your spacer is indeed in there (it looks like it is there in your pic, unless someone big-time botched a bearing job; in which case you'd have a load of slop in the hub). If those two measurements are OK; then its just a matter of getting the right stack of washer, nut, and cotter pin cage.
Can you use the original washer and nut and cage?? Assuming the threads are the same of course. Would that get you close to being right?