The area forward of the hinge line is called a spoon. You would see the same thing on Me109’s. While most modelers think of them as a way to dampen flutter (which they do) on most WWII planes they were used to reduce stick pressure for that control. The type of counter balance you should have for your P-40 is a static balance, normally containing some lead to move the CG of thee forward to reduce flutter tendencies.

Will changing yours to the correct configuration will not affect the flyability at all but be on the lookout for flutter.

How to make it right? Short of recovering I can’t think of an easy way to do it right. That doesn’t mean I would not consider the clear packing tape thing.

Joe