It's been a while since I posted an update, as I haven't done much work for a couple of months. I finally got back to the scroll a couple of weeks ago. I roughed it out with a small grinder and a carbide bur. The second pass was with a small chisel, the third pass with a combination of scrapers and machinist's files.
The profile isn't quite right. I think it's a bit deep, particularly in the actual scroll area. It's also not semicircular, but I can probably smooth that out. I have somewhere a short piece of surgical tubing that makes a nice mandrel for sanding these curves. Once I find that, I'll be spending some leisurely time sanding the profiles. It's slow, but at this point I don't want to rush the process. I'd rather take the time and sneak up on the target. As Andris says, "Measure twice, cut once. You can't stretch wood."