I'm building up a Surly right now, and I've been trying to go the eBay route for the build. I got a pair of Dura-Ace SL-7800 downtube shifters from a seller in Taiwan, but they only included the flat lever boss covers intended for alloy frames. Since it's going on a steel frame with small-diameter tubing, I need the rounded ones.

Right now, I have my local independent mechanic checking his parts bin for these, but if he can't find 'em, what are my other options?

Also, why would Shimano only include the flat ones? Are they sold under a different part number?