It seems to have a peculiar amount of chrome on it but I have seen a Super Record with a chromed brake bridge and I've seen chromed stay caps before but that was on older models than this. Maybe they did this as a custom but with old frames you never know how they've been tweaked over the years. The seat stay caps wouldn't be engraved on an SR, a bottom bracket pic would answer everything for you. Don't dismiss it, you could get lucky!