I recently came here looking for help much like you. I wish you the best in your endeavors. I'll update my own thread shortly but I had to very carefully repair a broken steering knuckle on a 1:10 scale truck. Investigating the circuit board revealed physical damage in the form of pulled up solder points and traces. Rather than even test to see if it still works, I pulled the circuit board from an ultra cheap RC car my son had. The cheap board was a quarter the size of the original to the point that it looks silly sitting in the old board's place. But along with the radio for the cheap car and the circuit board transplanted into the truck everything worked. You might consider something similar.
Where is the one you found in the US?
Good luck.