Between Two Worlds / Messages Found in an Oxygen Bottle

This is a dos-à-dos of Between Two Worlds (1986) by Terry Carr and Messages Found in an Oxygen Bottle (1986) by Bob Shaw.

• This publication is a dos-à-dos style hardcover with both sides containing a collection of short stories.
• Stated "first edition" and assumed "first printing." Note that the publication states "1986" on the dust jacket flyleaves, title pages, and copyright pages while the NESFA Press web site lists the publication date as August 1986. Locus1 has September 1986.
• There is an "Acknowledgments" essay on page viii of the Between Two Worlds side that ends with "Andy Cowan, Editor" over "Marlboro, MA" over "June 1986".
• The copyright page states "This is a limited edition of 1000. The first 225 being a numbered, slipcased edition" and "International Standard Book No. / 0-915368-33-1 (regular edition) / 0-915368-88-9 (slipcased edition)". The jacket flyleaves repeat the limited edition statement but also add that the 225 slipcased copies were "... specially bound, and autographed."
• The price is not stated on either the dust jacket nor the publication itself. The NESFA Press sold it for $10 at ConFederation 1986 and for $15.00 afterwards. Spot checks on 2005-09, 2007-02, and 2017-06-09 show that it is available for $15.00 plus shipping.