yes .i only have skype proofs.which is from every day.
You should get all the proofs you have and lets not worry about the things you do not have such as phone record from your end, as you cannot do much about it for now. I would make a cover letter explaining why your side of the phone records are missing and assure them that in future you will use a service that will show your end of the phone calling as well.
For now concentrate on the skype records, and all other things that you have. Take pics of the gifts you guys have exchanged and if you have visited his relatives or he has visited yours, and you have pics of those occasions add all those things. And explain these events in detail.
Even add things that you might think are not important, becuase every little bit counts. Because real relationship has many dimensions and to paint a complete picture of your relationship you must not overlook any thing.
One more IMPORTANT thing, your and your husband both should write letters explaining your relationship in detail. Explain how much you know him, how you feel about him, how living so far away from him affects your life. I am sure you can think of many things you can write about your husband/relationship.
Let me know if this answered your question.