Thank you everyone for these replies, there may be more to come.
I buy my organic seed from the Seed Cooperative, who also have a few heritage varieties. Its good quality seed from a community-owned seed supplier.
www.seedcooperative.org.ukI also get seeds from the Garden Organic Heritage Seed Library
https://www.gardenorganic.org.uk/hslBriggsy you are saving more than I do, but I am learning fast. Its getting a bit late now so I will be in touch again at the end of this year re swapping some seeds with you and hopefully by then I will have a few other people interested.
Chrismahon, I am also not registered organic, but I grow to the principles of 'feed the soil not the plant' and avoid toxins of all kinds, so its as organic as it gets. Your beans sound like they grow like fury in the warm air. I am happy to exchange beans with you but I don't grow squashes. I am growing a heritage French bean called Blue Coco from my own saved seed for the first time, so will update on the results later this year.
From last years crops I saved five different tomatoes, three chilli peppers and several types of beans and peas. These are all easy, they tend to self-pollinate and grow true to type. Toms have flowers that contain both male and female parts so each flower pollinates itself. I grow all heritage varieties obtained from Seed Coop and from the Heritage Seed Library and most flowers fruit true to type, even when I grow five varieties side by side in my poly tunnel.
Interesting what you say, Fleecewife, about your f1 toms reverting. I agree that beyond peas beans and toms it all gets harder. My cucumbers don't replicate true unless they are tens of meters apart, or isolated in some way. But hey - its great fun growing what grows easy, and its a good general principle for gardening up here in Scotland.
Keep up the good work! I will organise a swap club as soon as we have a few potential members.