+1 for Vermont Freehand, I purchased a few rods from there, excellent service.
Another possible source is Ebonite pen blanks, I purchased a few things from there as well, usually takes about a week to reach me, but otherwise excellent as well.
Thank you both for the VF referral. I have them saved as a favorite, but never thought of consulting them. They have plenty. I want it for kitless sections...is there a difference among the Japanese, German, and Indian ebonite?
I haven't used Indian ebonite though I have been tempted to buy some of the patterned rods from Ranga, they sell through eBay and Amazon. Since they also make fountain pens I think they should know what quality is needed.
I've had no problem at all with SEM (black and colored/patterned) and the Japanese black ebonite that VF sell. The Japanese seems to be a little softer - perhaps "smoother" -- than the SEM. It looks blacker initially, and polishes quicker.
When fully sanded & polished & buffed (the buffing is important, I find) the SEM is totally black and shiny.
I don't have any data on lengevity of the shine -- my guess is that the Japanese (having become shiny faster) might lose its shine faster.
One word of warning: I once bought some square rods of black ebonite from an Italian seller on eBay. It had tiny air bubbles which looked ugly, not many but just enough that I couldn't make a section without a couple of these blemishes