I spoke with Shawn at CVJ. We talked for about 15 minutes, he took my questions seriously, also asked me some, and we discussed the process a bit. Part of why I found his answers credible is that he remember our call a few weeks back, asked me what we had decided about the grooved inner axles (at the seal) (I got new ones), and was curious about price and source for the OEM inners (I suggested Derek at Stevinson and C-Dan). I told him about RS and this forum and how this write-up here and others' experience influenced me to try the rebuild.
FWIW, the Slee joints I just rebuilt I purchased in 2004 and probably have 90,000 on them. A good argument for what Christo said - $0.004 per mile, per side.
1) the black - paint. They paint every part that goes out. To protect the raw metal, and, because customers like the fresh look. Like a new part. He basically agreed the paint was feel good for most people. Probably also helps them keep track of finished parts. Its just regular spray paint, he says people install the painted parts into enclosed greased spaces like our knuckles all the time and he's never heard of a problem. He also said its a very light coat that should come off with some mineral spirits or goof off.
Note: if you don't want them painted, just ask.
2) The Grease - a CV Joint Grease, Hi Temp, Extreme Pressure, Lithium Base, Moly grease. He said they grease birfields with a better grease than other CV joints. He did not offer the brand or specific type but my impression is that its just because to him its the right grease, no greater specification needed. He did note that its Lithium based, so should be compatible with any other lithium base grease.
Note: I'm still unsure whether I want to mix it with the Valvoline lithium based moly I was planning to use. I probably will.
3) The process: new balls, cage and race (in the birf he said they consider the "star" the race). A "proprietary" process for the cup.