Where can you get parts for Remington model 95 derringer?

That's a really good question, they are hard to come buy without just buying a clunker for parts but get a matching model/type they are not all the same.

Watch gunbroker.com, I think gunsamerica.com also has parts maybe gunsinternational.com and auctionarms.com.

You might also try the forums on remingtonsociety.com