I've just bought 3 series steps from eBay for a tenner without fittings , I see there are two holes in floor of Landy by sill which I'm assuming are from a previous fitting so I will buy some off the shelf bolts . There is a very small hole where the support arm lines up, I'm assuming this is a guide to where to drill because I understand that a large rivet goes in there to support a bolt , rather than making the whole larger can I just rivet supporting arm in as I'm not keen on drilling into the chassis and understand you need a fitting tool for the larger rivet which I don't have

Thanks