When we bought the house, the tiny half bath off the master bedroom needed some immediate help. The brass drain pipe under the sink was so corroded I could poke a hole in it with my finger. It was also patched with duct tape...seriously. The original sink and mirror were also in rough shape. The sink was badly corroded and the mirror had a crack through it.
I honestly thought the sink was beyond repair so I started looking at every salvage store I could find in Minneapolis and on the internet for an exact replacement. It is a "Standard" so I figured it would be pretty easy. Fortunately, I couldn't find one and became determined to restore the original one. After cleaning and removing the rust, I used an epoxy called loctite hysol 1C which worked amazingly well. I finished it with a product called "Surface Repair" in plumbing white, which blended extremely well with the original color. I also found they don't really make drains for this size drain anymore, so I had to use a dremel to expand the drain until something would fit. The first time I reassembled it, it leaked in no less than 4 places. After some swearing, I regrouped and fixed the leaks.
Fixing the medicine cabinet was equally painful. I used Ready Strip to remove the six layers of paint it was covered in, which took seemingly forever. Once I got it down to bare wood (pine), I used Watco Danish Oil in Natural and Amber Shellac. Thankfully the shellac part of this went really well thanks to some tips I got at 3121 Park Ave during the Park Ave walking tour.