No mate the other way round a mrk 3collar will work with a mrk 1 the noise is slightly different but a mrk 3 box won’t pick up a mrk 1 collar if that make sense
Personally and it’s only my preference is no right or wrong way but i prefer to have my draw cord running through the bottom ring instead of fixed, like I said it’s just my preference, gets addictive once you start mate,
Those off torchey are a great bit of kit, I wouldn’t go out without mine, plenty of room for nets, knocker box,knife, game carriers ect, extremely well made too, often copped but never bettered, if your getting one go to torchey direct,