Transom Cap advice 1990 V20 O/B

[Disturbed]

I recently bought a 1990 V20 with a Johnson 175 O/B. Part of the transom cap is broken and missing. I want to replace the entire cap. Has anyone had any luck replacing theirs? I can't seem to find any info on the subject. It is 2.5" thick, and I'm not sure if I will be able to properly bend aluminum C channel if I find it due to the sharp almost 90 degree corners. Does anyone have any suggestions?