Gundel-Putz seems fairly benign [ http://www.objectsofuse.com/products/work/gundel-putz-stropping-polishing-paste#.VEJDsxZgGSo ].
Unipol seems to be abrasive (like Autosol a favourite used to remove rust from chrome on cars & bikes) [ http://www.hollisonsupply.co.uk/unipol-metal-polish-50ml.html ] HOWEVER
see [ http://www.weiblen.de/en/materials/cleaning-and-polishing/unipol-metal-polish/ ] from organ builder supplier!