Hi Rich,
Regards decal conforming.
If most standard decal solutions are not very effective, I have used 'Tamiya' X20A acrylic thinners.
If applied sparingly and left to work, it can soften and seal the decal into shape.
I've found it good on thick 'Tamiya' decals.
This is also handy for conforming decal over small, raised detail, such as wing strut attachments, wing foot boards and pre-moulded panels etc.
Mike