[Citroënbender]

Both Evap-o-Rust and Deox Gel are supposed to be safe for chrome.

The patina preservers like Eastwood’s one, are all matte - probably not what you’re looking for. I reckon a good buff with Autosol after rust removal, then wax and grease remover to remove the residue. Work in (by hand, with sacrificial rag) a double coat of a sealing oil with added polyurethane or just Penetrol, hand buff off the excess with clean rag and let dry a couple of days. Then rub the whole thing with Carnauba wax.