This is what I do to all of my vintage razors;
Soak in boiling water with a little bit of dish soap for about 5 minutes to loosen the heavy crud. Scrub with a heavy bristle toothbrush. Rinse. If the razor is particularly dirty it may take two or even three boiling water applications.
Soak in 90% isopropyl alcohol for about 5 minutes to sterilize and dissolve whatever is left. Scrub again with the toothbrush. Rinse. If your razor has any bakelite parts you need to be careful because alcohol will mar them.
Polish with Noxon metal polish (available at Lowes and Home Depot) using a medium bristle toothbrush. Rinse with very hot water to remove any residue.
It takes a little bit of work but I have not met a razor yet that I couldn't clean with this method. If the razor has pitting or is missing some of its plating there is nothing that this or any other cleaning method can do about it. Make sure you wear rubber gloves as boiling water, alcohol, and Noxon are not the kinds of things you want in contact with your skin.
"Two wrongs don't make a right, but three rights make a left."
- Zen philosopher Basha