This is a final posting on my experiences repairing Venture plastic.
Along with repairing broken tabs and cracks in various plastic parts, as described earlier, this last post deals with fixing/replacing broken posts on the side covers. broken posts are not an uncommon occurrence, especially if you replace the old rubber grommets with new ones. These will hold the side cover posts much more firmly, and increase the risk of breaking a post, as I did, when removing the cover.
I purchased a bag of plastic rivets from Napa. These are commonly used these days to hold all and sundry plastic parts together of ATVs and autos.
First cut the head off the rivet plug, and push it in somewhat to expand the rivet. Test fit the rivet in a rubber grommet to make sure the fit is snug, but not too snug. It's then a matter of gluing the rivet to the side cover mounting base, perhaps using a small hand-held grinder, or file to make sure the surface of the rivet and the mounting base are flat. I used Chem-weld for gluing the two together, as the rivet didn't seem to be ABS plastic. Once that set, a layer of fibre glass and epoxy was wrapped around the post base. Hopefully that will hold the rivet securely in place.