Hi Shane,
I think you have the basic concept right except I would do a few things a little different:
1) I probably wouldn't use an iron to heat the fret board. I use S.M.'s tool it 's basically a chunk of metal...the important part is I put a surface thermometer on it so I don't get it too hot.
2) I would use something thinner than a spatula to get started. Again, I use S.M. tools BUT an old fishing filet knife that you dull down would be excellent.
3) When you work off the F.B. try not to gouge or otherwise damage the top of the neck...you don't want to ruin what is an otherwise flat surface(should be anyway)
4) Don't use the fret board for a templet...After cooling they tend to shrink and warp somewhat. They make nice wind chimes and are also good for future repairs. Use the neck itself if you need a templet...but I wouldn't make a templet myself. I would make sure the new blank has a nice flat square edge and bottom and then I would slot ( using my S.M. table saw setup), radius the board ( using Craig Holden's radius machine), and then finaly taper to approximate size.
5) Next I would bring the F.B. close to actual dimension. Get a good clear center line and make sure it is square/parallel to the frets. make sure everything lines up square...drill some pin holes to make sure the F.B. doesn't shift during glue up and after gluing the fretboard to the neck I would clean up the slight overage that was left.
6) Even though you were careful and used a razor to score the paint/f.b. line there will probably be some touch up work needed. I hate this part. I realy dislike finish repair work...but it's part of the whole job so be prepared for it. Experiment on some scrap to see if you can get a good blend. I hope you are getting well paid for this!
Next year we he want's the fret board sanded hit him in the head with a hammer...when he wakes tell him your all done!
Good luck! Have a Merry Christmas!