In the end all of the tomato seeds germinated, with the exception of two "Maskotka" ones (together in the same pot).
Now the seedlings have at least a couple of true leaves each, as well as their cotyledons (aka "seed leaves").
The Chillis are comparitively slow developers. Not all of them have germinated yet, but they are continuing to do so - one or two more every day.
I have put all the ones that have yet to germinate into the airing-cupboard, where hopefully the extra warmth with give them the necessary "wakeup call".
Elsewhere I now have a couple of new Aquilegia plants - albeit very small ones!
These ones have been grown from seeds kindly sent to me by Jo from awholeplotoflove. She sent me seeds for three different varieties, and I sowed some of each. So far only these two seedlings have emerged. I was a bit concerned about this, but when I looked at the seed packets I saw that it says "Germination my take 1-3 months" so I guess I just have to wait a while longer!