International Paints have kindly offered to send me a sample of Interstrip AF: http://www.yachtpaint.com/gbr/diy/products/special-products/interstrip-af.aspx
Cirrus Systems Ltd have agreed to send me a sample of their RemovALL 620 product, which is biodegradable and non-toxic: http://www.cirrus-systems.co.uk/index.php/Marine-/-GRP.html
My gratitude goes to both of theses companies for helping me in my studies and being able to give me first hand experience of their products.
I am still waiting to hear back from Owatrol to see if they would be willing to provide any of their products for testing.
I have decided not to use Hempel's product http://miniurl.com/123820 as unlike the others it does not claim to be safe on glassfibre and gelcoat "Use with caution on glassfibre and plastics (may harm some thermoplasts)" so I would would rather not take the risk on my precious hull.