this case is for ultra , but i think you can try scale (x 86.5%, y 92% , z 75% ) , i dont have 45mm iwatch to test this , if it work or not , can you send me a photo let me figure it out.
The Apple Watch Series 7 (45 mm) has a height of 1.77” (45 mm), width of 1.5” (38 mm), depth of . 42” (10.7 mm), and weighs 1.37, 1.59, or 1.82 oz (38.8, 45.1, 51.5 g). The screen size is 1.77” (45 mm) diagonal with a resolution of 396 x 484 px at 326 ppi.
doesn't work with the rounded edges just wobbles and crap on the 8. fucking awesome on the ultra though. would need a redesign to get it working on the normal series apple watches