cover FORWARDING AGENTS' CACHETS: 1863-75 envelopes (3) to Melbourne, each with a fair to good strike of "OLYPHANT & CO" on reverse; two are with Hong Kong 24c. green cancelled by "B62" and one with Straits Settlements 24c. tied by dumb cancellation and company oval with Singapore Paid c.d.s. in red alongside. Endorsements on face indicate that two originated from Foochow and one from Hong Kong; Singapore cover with small stain on face, an interesting trio