[snowyskiesau]

Fibreglassing is not that difficult to do.
The hardest part is making a strong, reusable mould.

A form of of section of the dome is made from MDF ribs with a plywood covering to get the bend correct. You may have to steam the ply to get the correct curves.
This is then used to make the mould similar to the one in netwolf's link. I'd probably reinforce the mould with timber as the stronger it is, the longer it will last - and it makes it easier to get out the finished panel if you have to use a bit of force!

Making the mould is a matter of preparing the wooden form so the gelcoat/fibreglass doesn't stick ( polish with, carnauba wax and apply a mould release). Gelcoat and several layers of fibreglass mat and resin are applied to the form and that's it. The trick is making sure the mould releases from the form which is where the waxing/mould release comes in.
Making the panels follows the same routine.
Provided the mould is kept clean and in good repair, it would last for years even with regular use.

This is all from memory, it's been a few years since I did any of this,