@bigarse1 how about bubbles? Different types of machines, wands and touchable ones etc? I did that for dd one birthday she got a little indoor trampoline and every type of bubble thing I could find lol.
A tray (we have a concrete tray from b and q) some different types of figures and things like shaving foam, pasta or water beads to make a sensory tray.
Different texture balls, those click clack car towers always go down well with the children I work with with asd they like to just watch it go down over and over again. I got dd one of the musical ones that go up the stairs and slide down last year she loved was about £3. Liquid timer type toys, a find it (tube with rice and things hidden to find) water beads, lullaby/projector light for bedtime? My dd has loads of different types mostly from argos. Foil blanket, bendy men or a stretch Armstrong, tangle toy or other fidget toys.