https://www.ema-models.co.uk/

ema

Quote from their website:

Our materials include; tubes, bends, tees, reducers, domes, cones, stairs, ladders, square and round tubes, acrylic rods, plain and patterned sheets, fences, meshes, figures, vehicles, furniture, structural profiles etc. Create your street scene, skyscraper, oil rig, castle, submarine base etc. from thousands of professional engineering model making items, allowing you to prototype any project.