Solar Panal Removal and Re-fit.

I am "considering" removal of the large solar panal fitted to the roof of the van, primarily to replace the eight fixings ( nuts and bolts) which secure the units alloy  frame to the four alloy angle brackets in turn fixed through the  roof skin with what seem to be self tapping screws, with white sealant/adhesive.
 The offending eight bolts are a mixture of hexagon headed and large phillips type screw heads, this mixture reflects badly on who ever fitted the panal, they are rusty and un-sightly. It may be that the panaol has been removed in the past.
The bolts pass through the  solar panel frame and brackets and secured with nuts / washers. It is not possible to access or hold the nuts on the inside of the frame with a socket or spanner. Hence the need to release the unit from the roof to access and replace the  corroded fittings with stainless steel nuts and bolts!
My concern is the refitting of the unit and its brackets to the original fixing points into the roof skin. Will any replacement self tapping screws be compromised?
This  depends on what the fixings anchor into via the roof. Will any additional wood or other support exist immediatly under the fibre glass skin to recieve the self tapping fixings?
Has any one removed or replaced a solar unit on an Exec roof of this type. Can any one confirm what the self tappers may screw into and the composition of the roof. Any advice / experiance will be appreciated. I would hate not being able to refix the unit correctly and securly with new fittings, adhesive and sealant.

Obviously I could leave well alone and simply treat the rusty bolts in situ and paint them, easy solution!!!!


Regards

Carlo

I took the panel off our Executive when we swopped the van.  I decided to leave the brackets on the roof and drill through the rivets that secured the panel to the 4 brackets.     Where the cable came though the roof i mxed some white paint with filler to fill the hole.

The panel has been on the Windsor now from new

Why not just put some masking tape around the bolts to protect the roof surface and then get a small wire brush, clean up the fittings - much easier and when done you could perhaps put plastic caps over the bolt heads, and you might also consider spraying the fittings with a waterproof seal. There are lots of various size plastic caps on domestic products that might do this and then just seal them on with a blob of silicone and wipe clean.
Mike