Yes I had. You'll see yours was made by (or rather for) Madison in their early days. In my experience they were all generally made of 531 - e. g. ST for ROMANY, C for RAPIDE model. Having said that I now have one of 501 throughout!
That 4130 sticker on yours looks too new and a bit wonky in my opinion to be accurate. If a genuine Rapide expect it to be built of Reynolds 531C. Looks like it has had a dodgy repaint in the past? EDIT on 2nd thoughts the paint looks original. This is a bike worth saving.