With the help of a couple of good friends, it took +/- 1.5 hours to successfully replace the broken piece. The top has not worked as smoothly in years!

The 91 piece, which I would characterize as "main" fits perfectly with a little effort. The screw holes, as identified in the attached image, had to be drilled and tapped for 8 mm in lieu of 6mm; at least in my case. I did not have the screws from the '91 and could not locate replacements, so I had no option.. The 6mm may have worked with spacers and washers but I do not think the end result would have been as satisfactory.

Also, on the 88 there is a +/- .5" spacer that we eliminated due to the fact that the thickness of the part had been increased proportionately in the 91 part. see image.

Frankly, I think using the part the part from a 88 on a 91 may be problematic due to additional parts attached in the 91.

Today, I authorized spending a sum witch increases my cost, through the last 2 weeks, to greater than the apparent "value" of the vehicle. New stayfast top (you can see from the pic that the original looks like crap) and recovering the driver's seat with leather and fabric.

My love affair with my Camaro continues after 20 years.