A couple of Airtech's Moto Guzzi Le Mans fairings are squared, might work.
Here's one like Teazer's example.
https://www.ebay.ca/itm/Tracy-Front-Fairing-Headlight-Windshield-Cover-CB-GS-XS-Z1-KZ-900-1000-1100-Cafe/293153882441?hash=item4441554149:g:5lAAAOSwRPBdFWxV&vxp=mtr
Here's one like Teazer's example.
https://www.ebay.ca/itm/Tracy-Front-Fairing-Headlight-Windshield-Cover-CB-GS-XS-Z1-KZ-900-1000-1100-Cafe/293153882441?hash=item4441554149:g:5lAAAOSwRPBdFWxV&vxp=mtr