Congratulations on the new to you RV9.
There is no "part" called a trim wedge. This would have been added by the builder to try to resolve a heavy wing. I have seen everything from trim tabs to coffee stirrers attached to the aileron.
Keep looking in the archives. The RV9 has a different wing trailing edge than the 6-7-8 and requires different techniques.
On my particular plane, the final solution was moving the aileron hinge bracket to lower the leading edge of the aileron.
Make sure you really have a heavy wing. If you are flying solo, there is a heavy weight sitting in the pilots seat that can seem to make the plane turn left. My usual practice is to try to keep the left tank 6-8 gals less than the right to compensate.
A good way to quantify the amount of heavy wing is to run the heavy side tank until the plane balances and note the amount of fuel required.
RV-9A N946PM 600+ hours since 2013