I have formed an initial opinion that the FDCs for Tonga and Upper Volta are possibly unique or in such few numbers that they have not seen the light of day in the major collections of the past 20 years. I have the 1977 Tonga set spread across three FDCs, two of which are registered. They are all addressed to Etter himself. These are probably the pick of all the Etter covers ever made for thematic relevance of cover, stamp and postmark.
For Upper Volta I have one set with FDC, and one similar cachet cover also dated with the first day postmark, but not stamps attached (i.e. serviced without stamps). These again are addressed to Etter himself.
New Postmark Additions
||7 March 1978
||Arrival New Albion, Cape Perpetua (also known with Yachats, OR cancel)
||12 July 1978
||Nushagak Peninsula (I have only seen a date of 12th July, but the original list has a date of 13th July). Also note that the cachet has a date of July 12 – 13 (not 12 – 18) as in the original listing.
New Cachet Production Materia
I have in my possession for the first time a cachet that is neither printed directly onto the envelope, nor on birch bark, nor on silk. This cachet is printed on a glossy stick-on and added to the envelope. It is the only one I am presently aware of, and it was used for item 70.1 off the list compiled (Elim, AK on 11 September 1978 – Explored Norton Sound).
Extra Useful Information
Check inside your Etter covers for useful information. Etter produced his covers in very small numbers for the original subscribers (30 covers for each edition as a general rule-of-thumb). Some however are possibly unique (or unique over ‘one set’ of stamps making a few covers). On my exploration website I have copied an original hand-written message by Etter to one of the early subscribers. It is for the 16th Jan 1979 cachet (item 95.1, which is a typo and should be 96.1 on the previously published lists). This is to celebrate the bicentennial of Cook’s discovery of Kealakekua Bay, Hawaii. The note written by Etter states that only nine of these covers were made, and for the collector to keep this information private (so as not to offend and upset the other subscribers!). He also states that approximately 30 covers were made (normal production) for the 17th Jan 1979 cachet (item 96 where Cook lands at Kealakekua Bay).