My wife recently convinced me we need a bimini for the rear seat of the Mariah. I would like to mount it to the rear grab rails with straps to secure to the stern eyes and the tower. Thought of drilling and mounting this is dreadful to me. Question: Have any of you done this?

I've seen clamps on ebay that wrap around the railing then provide a place for the bimini to mount. Is there a standard diameter that Supra was using in the late 80s/early 90s?

Thank you all for your help!