Take a large piece of paper, set it over the form in question, and trace the outline of the form. It doesn't have to be a perfect tracing. Fold the paper in half, with the lines on the outside, and try to match the front of this stack of pages with the back.

If the images line up perfectly then your form is the right (symmetrical) shape, but it is positioned on your strong back to one side. Ee mount it. Let the already placed strips help you center it.

If the images do not line up perfectly, then go back to your plans and, with the aid of your tracing, determine which side of the form is the correct shape. Once you know that, by comparing the two sides (hold the folded sheet up to a window and let light shine through boath pages) you'll see if you have to glue on small pieces of wood to build up one side, or if you need to trim more off of the other side. Take either of these corrective actions and go back to your stripping.

Try to fix things with the form mounted on the strongback. If this is not possible, then make lots of alignment marks so you can get that form, and any others that might have to come off, back into the proper position with the least amount of effort.

It is a good thing you discovered a minor problem early in the stripping process. Even if you have to pull off all the strips you've applied, once you resolve this you'll be able to re strip that area very quickly, and future strips will go on a bit faster.

Good luck with your work

PGJ