Each ALDA is set to its IP on the bench. The only way to match a new or used ALDA is on the bench. In the absence of such facilities, it doesn't matter how the ALDA is oriented on the IP since it's not a factor of adjustment. I guess I only repeated what Peter said.

The fun will come in tuning the new ALDA. Do youself a favor and remove the wax and shield from the adjustment nut before you install the replacement ALDA.

Sixto
91 300SE
87 300SDL
83 300SD