Good to hear you're getting a replacement :good:
Just as a general thing, any decent epoxy putty should be able to cling to an area of resin this small since you can sculpt new ears and noses without them being so delicate that you'd be worried about them popping off with a bit of handling. This is assuming there's nothing on the surface interfering with the bond of course, and that the epoxy putty is up to snuff. I'm not a fan of Milliput but it should still do it if it's fresh enough, if not then Kneadatite (GS) sure would.
Something that projects like this is still prone to being knocked free with a casual bump, so one simple tip to help a better bond form is to drill small holes into the surface at opposing angles but not for pins, when you smoosh the putty into place it'll go into the holes and these will act as an anchor - the putty would have to break for it to fall off then.
Still better to sculpt this in stages: form the 'keel', then sculpt the detail as a separate step. Either that or make it overthick, then pare/carve down.
Einion