You probably need more than one person for the various tasks:
1) transliterating the handwriting into legible Russian in modern spelling,
2) understanding the meaning exactly and reproducing it in English,
3) writing it down in good English.

Often 1) is the most difficult task; for this you need a native speaker who has some experience with historic language, spelling, and handwriting. It would be a coincidence if that expert were also good at task 2 and 3.

I had the same problem with my family heritage (just letters etc.). Although I have some elementary Russian, I heavily relied on several friends to decypher the old texts and documents.

As JohnIK wrote, a search in the Russian Orthodox community may be the best idea.