Bekircan Tahberer suggested (on the coinstudies list) that RPC 7, 8, and 9 have been finished by Edoardo Levante but funds cannot be found to publish them.
Volume 1, which sells for $700 and is offered at even higher prices, indicates a desire from collectors for the series. Perhaps the British Museum Press doesn't think academic libraries are ready to acquire the rest of the series, and that they make up the bulk of buyers?
RPC 7 part 1 is to be published this year, so mr. Tahberer is perhaps talking about 7 part 2? David Brown Book Co is offering the title and claims the author is Marguerite Spoerri Butcher. Amazon is taking pre-orders, and claims the authors are Ivana Marková, Per Linell, Michele Grossen, and Anne Salazar Orvig.
I stumbled across a thread on Collectors Universe on the economics of publishing books on US numismatics. The post by user and book author C. D. Daughtrey (AKA 'coppercoins') is especially worth reading.
'coppercoins' claims that although 'the Red Book' has a print run of 75,000 copies the typical book on US coins has a run of 1,000 to 3,000 copies. Mr. Daughtrey self-published his book and quotes his costs. Looking Through Lincoln Cents is paperback, spiral bound, and only 5.2"x8.8" inches, assume a bigger book will cost more. Amazon seems to offer an earlier edition, and has 'Search inside this book' enabled.
SOS SS United States - It's now or never to try to save the fabulous SS United States from the breaker's yard. The downside is the cost of a refit for commercial use, but the up...
1 day ago