Murray,
You should be able to login to the "outside" interface from the internet having the proper configuration; you can be very restrictive so the SSH/ASDM access is not wide open.
There is a command management-access that should be reserved just when you want to manage the ASA using an internal interface but it is reserved just when you are connecting via VPN. I have seen it working once when comming from the internet (without VPN tunnel); but this is something we don't support. As I stated at the beginning managing the ASA using the external interface should be secure enough.
HTH
Luis Silva
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Luis Silva