There is a guy in the Indy area that does p48 conversions. He might also be wiling to do 3-rail to 2-rail. If he can do p48, he can do 3-rail to plain old 2-rail. I think his business name is Hanson Rail Service or something to that effect. He had a table at the Indy show this year, and he's the guy that runs the p48 meeting at the Chicago and Indy shows.
Matt Forsyth is definitely a good option as well.
EDIT: well, I got part of that wrong. Wrong Hanson. I think Paul Hanson does the p48 meetings, and Jim Hanson does the conversions. I still don't have any contact info for him though.
Jim