I've never heard of such a contraption! Heat pads yes, but not wet ones
I think it's probably a bit specialised to be able to find in a general shop! I've taken note of the condensation to show good humidity though
I've finally done the change-over:
Everything is now contained in a yellow transparent plastic tub. The lamp is stacked on top of books to be able to get in the tub at a good angle. The tub is covered with a tea towel which is fastened with clothes pegs.
This shows the whole of the lamp. You can see the base stacked on top of the books, with the actual light angled down into the tub and a ruler to raise the tea towel at a certain point to stop the hot head of the lamp touching the towel.
This final picture shows the contents of the tub quite well. The lamp at the top as mentioned before with the ruler raising the towel, the eggs are still in the scarf but not covered with it anymore. I have put two water bottle lids of water inside to maybe help with humidity, plus the damp towel. Finally the thermometer to give a rough guide to the temperature.
I hope this new set-up will give the eggs the best chance of success. If anyone has any comments, advice or improvements I could make, please let me know!