.001 over 6" is pretty dang close. I don't know that you will be able to get it any closer than that. Once you get the column itself sorted out, you won't have to worry about it again. Then all you have to worry about is the head itself.
Well time to post a picture (if I can figure it out) and some first impressions. Went the rout of building my own stand which turned out ok although two more inches taller would be ok.