I have had a few decals done on my bikes. Check for local sign and banner shops. I have used two shops in my area. One job was to create reproduction Schwinn decals in white vinyl. I rolled a bike in that had the graphics that I wanted copied. They snapped some pics and took some measurements. Two days and $10 later I had a full set of Schwinn decals.
You might check with member axspul, he has the computers and tools to do the job.