I'm not aware of any o-rings for the engine oil lines. I thought these were all flared fittings. The only o-ring I recall is between the oil cooler adapter and the oil pump. Is this the one you need?
I do recall a gasket between the turbocharger and the oil return line, but not an o-ring.
I can't think of any on the transmission oil lines either.
Can you provide some additional details, please?