Kayvan, Thanks for sharing the information.
I went through a similar exercise some time ago to try to find a suitable off the shelf front bracket. I gave up the idea because I wasn't satisfied with the position of the license plate using the OEM brackets. My taste is for the horizontal center line of the bumper to be more or less the same as the horizontal center line of the plate. I have a "fake" modern style German Plate that I sometimes use that accomplishes this.
The other front tag I use is the original aluminum Zoll plate that came on the car when delivered. It is also mounted in the shared horizontal center line manner. I fabricated a backing plate to provide better support and used the original mounting holes to mount the plate. I extended the backing plate on each side of the Zoll plate to mount my Silver Star Preservation Badge and the soon to be delivered SL113 group badge! A similar backing plate can be used for the standard front license plates required in states such as yours.
Rather than post as a guest we welcome you to sign up as a regular member here on the Forum. It is money well spent. The pictures of your car that you have shared look great. We would like to see more.
Thanks again for sharing the OEM bracket information