Aircraft Serial Number Restoration Project.

This looks tough to do with the posted photo...it’s hard to think of what tools will easily distinguish the characteristics of the paint from the metal.

It would be easier if there was a way of more clearly seeing where all the remaining paint fragments are. Of course someone could probably use scientific equipment to isolate where the tiniest remaining paint fragments are on the metal, but we’ll assume that kind of equipment isn’t handy. With a normal camera, you might try exploiting the difference in reflectivity between paint and metal. Some ideas:

• Re-photograph the serial number area from different lighting angles, for example by moving the camera (to get a different angle of room lights vs metal reflection) or moving a handheld light at different angles as multiple photos are taken.
• Try a range of diffuse and point light sources, in case one works better. 
• Try applying some color filters (on camera or during editing), to increase any color difference that might exist between the metal and remaining paint fragments. 
• Maybe take a video instead so you can replay all of the angles as the camera and light are slowly moved around the area. 

Hopefully a certain angle and light can be found that causes a different enough reflection between the metal and remaining paint that more of the serial number can be recognized.

Good luck…I remember building a Dauntless kit as a kid, and a few years ago I watched a restored one flying.

Is that a B-24 Liberator?

The numbers look like

B-24 A,H, or R

503