my mom as a big fan of "oh, foot". Thats the only way it was ever used, though. It was never used like "foot that", or "where the foot is it?" just always "oh foot".
I don't know any archaic oaths, to speak of. I do love to tell people that I bite my thumb at them. Being in the US, I also use "bloody", "arse", and "shite" a lot. It doesn't seem to be taken with as much offense around here.
good grief was another one my dad was very fond of. Growing up that was probably one of them I used the most. But I don't believe I ever used it correctly.