I know it's a much smaller scale, but when a guide at Tangmere museum, ANY kit or memorabilia loaned or donated was signed in with a simple form, for both the museum and the donator / lender's records.
They also receive a nice little letter of thanks shortly afterwards; if a 99% volunteer group can manage it, one's blood fairly boils that well paid 'professionals' actually in the force being commerorated can't do a proper job...