Sounds like a big job for such a small area. The only part that would be able to be stripped and polished is the lever arm, and as mentioned above it would need to be removed before stripping otherwise you are likely to damage the adjacent plastic/rubber parts. Shimano brifters have never been made to be pulled apart and while it can be done, it's not exactly an easy task. If you go through all that I'm not totally convinced they'll look any less modern. Sure, if you've got some other polished parts on your loyal steed it will look consistent. Report back with the results.