My instinct was 1-2-3-4-1-2-3, but when actually doing it I kept coming up with 1-2-3-4-1-*3-4*. I have no idea why. Piano lessons were a long time ago; I assume this would be considered an error. (Not my instinct -- what I actually did.)
I think 1 2 3 4 etc is probably more accurate but 1 2 3 certainly works easier for those not too familiar with fingerings - Jo often corrects my weird choices so I've no clue what is accurate yet!
Thumb under, definitely
Re: Thumb under, definitely
Re: Thumb under, definitely
Re: Thumb under, definitely