Can't you put a 'detect magic being cast on object', 'cast wind of mundane silence or similar at the detected spell' combo as an active counterspelling attempt? Also, the various "mage an object appear magical or nonmagical", "sense scrying" (the one book talking about wizard war), "show false image", could all be used as part of a defense.
What I would do, since the object might not like extra magic on it, is put the object in a box and magic the heck out of the box. ReTe to keep what's in the box from shifting in transit (magical bubble wrap), MuTe with req to change the object into something more durable, PeIm to destroy any species in the box to make scrying more difficult (If an object is inside a pouch, I think scrying shows you just the inside and you can't 'zoom out' to see what is around the pouch?), ring wards on the box edges, etc etc. Also, this should reduce the Warping on the object to be protected.
A bit of a personal interest for my Verditius glassblower. Started with a display shelf enchanted to keep objects inside from falling off or chipping. A spell similar to Supple Iron to make it tough while in use. Eventually working up to a breakthrough, either a new Verditius mystery based on Items of Quality that would give a damage resistance bonus, or giving an object an Essential Trait relating to not being broken. Hmm, external souls & similar show up in faerie tales, but I suspect that even a Magic realm external soul would have an Essential Nature making it vulnerable to one specific thing.