Old steamer, to use over a pan (Elham CT4)

An old aluminium steamer, with trivet, tray and lid, to use to steam vegetables etc over a pan (ideally while something else is boiling in the pan, e.g. steam green vegetables while boiling potatoes, to save electricity and free up a plate on the hob).
Diameter approx 21 cm. The ridged base of the steamer allows it to be used pans approx 15 - 21 cm.
The lid in particular needs a good clean, but should scrub up fine. (Sorry, but it's been stored for a long time, and I have far too much to clear to be able to scrub everything first.)