Need floor plans made on existing home

[Tom Bettis]

I am under contract on a multifamily property that was originally zoned as a single family residence. At some point in the past, it was converted into duplex/triplex without proper approval/permits. I talked to the city and they said they would grant the change but need to see floor plans first. Does anyone know a Missouri-registered professional engineer or architect who can draft plans on an existing home for a fair price?