Here are some Dynamic Component Steeldeck rostra, which I adapted slightly (with his prior agreement) from the ones by Rory on the 3D warehouse. Mine allow typing in the height you want, his had a pick list with metric-equivalent of imperial sizes.
Sizes are in feet.
Steeldeck DC 6x3.skp (159.5 KB)
Steeldeck DC 4x4.skp (136.7 KB)
Steeldeck DC 8x3.skp (170.3 KB)
Steeldeck DC 3x3.skp (148.3 KB)
Steeldeck DC 8x3’3.skp (176.6 KB)
Steeldeck DC 8x4.skp (167.9 KB)
Studio seating guard rail 3ft.skp (90.0 KB)
And a staircase, with optional risers and banister rails.
Stairs DC.skp (257.5 KB)