Reacquiring Unique Starting Equipment.
There’s a very simple and easy workaround for this, but it will require an open character slot.
Simply create a new character and transmute the skin in question onto a white-quality gear piece. Doing so will make the resulting item Account-bound, even if it was previously Soulbound (as the starting gear pieces in question are). If you’re lacking in basic transmutation stones, completing map exploration for the character’s racial town will grant 3, and takes a matter of minutes.
I don’t believe this workaround is applicable for the Engineer’s multitool backpack, as there are not, to my knowledge, any white-quality back items.
That said, having profession trainers sell skin versions of these items would be nice. It would make it a lot easier to, for example, use the Visionary’s Helm alongside the Fanatic’s Pauldrons, items which match beautifully but which the player is required to chose between.