Yes, I think Trevor’s comments are more to the point. Don’t worry about the glue type just do good work. Also, there is a bit of guidance on hull repairs on plan B12388 if that reference number is still used. Filler powder with the West system epoxy products are what most people use and peanut butter is a good description of the viscosity. Other epoxy products are good too. Be sure to scrap off all the old glue. Most people don’t have any problems with UV and radiation, the effects of UV , radiation and salt take many years usually so as Trevor says it’s not a problem for most people. Wet out the epoxy on both faces of the lamination without filler first for best results.
Also, in regards to your question about the heat gun. It’s ok to heat the veneers before applying the epoxy but not after because the epoxy will “out gas” (creates small bubbles and therefore voids). Best to start with a slightly higher temperature and let it cool down. Humidity can be a factor too, do it on a dry day…. but in general epoxy is very forgiving. It’s easier to clean up the surface by removing the excess after a partial cure rather than sanding all of it after it hardens.