Rennaisance makes a very good de-corroder; this will work well in the pitted areas after the rust has been removed .
PM if you need a source .
Soaking in acid fruit juice, Pineapple; would remove most of the crud from the blade .
Coca Cola is a great rust remover .
The handle is a problem unto itself .
Maybe the Rennaisance de-corroder would be a good choice for the rust on the hilt .