Shroud extension center arraignment nut

My Mrod needs center arraignment (maybe rubber O-ring supported construction of shroud) when I attach my 7” long extended shroud. So I made a tapered Flat Face Nut (FFN), inserted between shroud adapter and shroud extension. FFN is slightly tapered face brace nut, to compensate the center arraignment. The below photo is FFN

I use laser bore sighter for adjustment as below sketch. First, remove the bolt lever and insert Laser bore sighter. Then, attach a paper on the outlet of shroud extension. Laser dot appears on the paper, which is out of center. Turning FFN to move laser dot to center.

I purchased this brass flat nut at a hardware store and sanded face as slightly taper, works well for my 7” long shroud extension. Below photo is my first center arraignment device which is heavy and costly, works same way.