Dear sir or madame,
I am writing to inquire whether you still require a translation. I would gladly translate the project you advertised along with any other documentation you need translated. I have translated PDF files in the past so I know what I am doing. I look forward to working with you and delivering what is asked of me in the shortest amount of time possible. I strive towards accurate and thorough translations so you needn't worry about their quality.
Yours sincerely,
Baso Basovich