Yes; we would expect any particular T-34 to be assigned to a named patient for as long as s/he needs it ... and ultimately given up to whomever is willing to accept it.
But if the "groups" wish to remain anonymous (and, to be honest, I can't really see why, myself), perhaps the secret details (aka
'phone number, post code or what-have-you) could be squirreled away on the inside
of the casing (for example).
Failing that, some sort of universal (but hopefully) logical coding system (known only to the healthcare illuminati
) could be devized.
As Lee has discovered, CME can only advise who bought the thing ... not where it currently belongs. But a simple database could be maintained (by somebody - how about the NHS?) where organizations could assert ownership of T-34's by serial number.
Other than that, why bother returning them at all ... but rather simply share them across the NHS, wherever they may be (or end up) and replenish from Central Stores (what Central Stores?) when stocks become low.