I have ordered several Seth's for customers without covers but like Lew said the cover is easy to remove and there is a chance you will get double creams if you go with covered ones. Duncan doesn't lower the dealer cost much for the uncovered one's either, so it only saves you a few bucks to order it that way.
Either Lew or myself can check bobbin color for you on covered pickups. I do it all the time on Seth's and Antiquities.