I am a professional audio engineer & musician, have been playing for 20+ yrs and have played on dozens of recordings done in Canada, Nashville, Memphis and Chicago. I can add some acoustic rhythm guitar to your song.
Basic rate is for one verse & chorus of the tune or a solo, if you've recorded to a click track you should be able to copy and paste at will. If you've got other parts e.g. bridge or middle 8, variations etc. just purchase one more gig from me to cover that.
I would ask that you credit me in the liner notes/online and let me know about it if the project is for sale or is for an ad, jingle etc., just so I can add it to my resume and link to it from my page.
I provide you with an MP3 mix with the part I played, and a 96k WAV file of just the acoustic guitar so you can put it in your mix