Which one to start with?

[Mans]

Hi everyone! I am new here and have a question. I just found two old razors that have belonged to my grandfather and would like to have them renovated. Which one should I begin with?

The first one is from Germany and says PNP and (probably) Solingen (the first part of the word is covered by rust); on the second side it says 652(...?) and PUT (...). Apart from some rust, the blade itself seems to be in good condition.

The second blade is less rusty but smaller, it is from Challenge Cutlery Co., Bridgeport, Conn.

Both blades have simple cardboard boxes, the German one marked with the PNP logo and a small note of warning in German inside.

I have attached pictures of both razors.

Sincerely,
Mans Broo