Converting plans into laser cut images

Hello

I am looking to convert radio model plan parts into laser cut images

Attached is a typical example of a plan image.

What would be the best way forward to convert the formers F-3/F-4 into laser cut files. The only part that needs to be cut is the inner surface shown by the squiggly lines, the other outer parts are the added parts for the build

I have tried to scan to a pdf, and erase the unwanted parts but the image is just too grainy as you can see in the Lightburn preview. I could clean up the image but would prefer to find a way of Lightburn (or other image editier package) recognising the lines and extracting these for the laser to cut

Hopefully someone has done this before and found an easy way to do this

Many thanks for you your help

Ian

Lightburn preview.png

FormerScan1.jpg

Prepare the scan with Gimp or so, then cut out the part you want and use an online image to SVG converter, check how it looks, adjust until you have a vector graphics that fits what you want to cut.