Hi Heather.

I see about 10 things on your list I'm interested in, including marigold colossus. Here's what I have to offer, have a look and see if there's enough there to interest you in a trade:

Aguilegia - Columbine - Nora Barlow
Alyssum - Carpet of snow
Annual - Fuchsia petunias
Anthemis tinctoria - EC Buxton
Aquilegia - Columbine - dark purple
Aquilegia - Columbine - Red star
Campanula - Blue clips
Cheddar pinks
Echinacea (purple)
Gaillardia - Blanket flower - Arizona Sun
Gaillardia - Burgundy Blanket flower
Gaillardia - Oranges & lemons
Heliopsis - Loraine Sunshine
Kiss-me-over-the-garden-gate
Lychnis - Maltese Cross
Myosotis sylvatica - Forget-me-nots (blue)
Mystery hosta (glossy green leaves, dark purple flower)
Primula vulgaris - spring-flowering primrose - magenta & yellow two-tone
Rose campion
Scabiosa - Pink
Sweet William

Laura.