At 1 mine loved puppets, the puppet company ones were lovely. I remember we had a big bird that honked!
I havent seen it suggested yet but mine loved the bilibo (it's like a plastic tub, you can kind of spin in it or use it any way you like imaginatively) we had it years, as they got older it became a cauldron for potion mixing, a hat, bed for a Teddy. It was great, at 1 he would probably like filling it with things!
Sensory light things, like a bubble tube or you can get light boards too which he might not use right away but could grow into. Mine loved a disco light when they were younger!
Or something that they could both use, a tuff tray and stand, we used to use one in the garden for messy play. Or setting up toys with water/sand. You can get waterproof covers for them too so you could leave outside.
I also agree with a scuttlebug ours was invaluable for park trips and days out as it folded up under the buggy!
And our tent got a lot of use. We had the circus one from IKEA, when not being used it was flat so we could store behind the wardrobe or bed. Still in use now occasionally and youngest dd is 10!!