Having located the missing panel from my greenhouse and found my stock of glazing clips at home, I came down early to refit the panel. Fitting it was easy but originally there was a stiffening strip along the bottom edge that was meant to stop the panel stretching out of its mount. It had failed to do its job and was missing. I found a length of cane and bent it across the bottom to try and replace it. I think a strip of exterior tape is called for.
The following day I grabbed the chance to pop down and tape the bottom edge of the roof panel after cleaning a strip along the edge. I managed the important one just before the rain came down and I went home!