1893 Columbian Issue

Is there a definitive handbook for these issues?

Not that I know of, personally.

There is a nice collection/exhibit of the Columbians available as a .pdf on the Siegel Auctions website:
http://siegelauctions.com/exhibits/...nExhibit.pdf

Other exhibits on the site can be viewed at: http://siegelauctions.com/exhibit.php

There were also a couple of specialized auctions of Columbian collections by Siegel. You can check out:
http://www.siegelauctions.com/dynam...?sale_no=952
and http://www.siegelauctions.com/dynam...sale_no=1055

What information are you looking for that isn't available in the Scott Specialized catalog or one of these sources?

There aren't any handbooks of the entire issue that I know, but there are many manuscripts and articles dealing with specific aspects and specific stamps written over the years.

The closest thing to what you are asking:
Lauzon (1942)
The United States Columbian Issue 1893

Other works of interest:
Coulson
United States 1893 the Two Cent Columbian Issue

Blaikie
Two Cent Columbian A 60 Year Study

Stamp Specialist Chartreuse Book
Study of the Dies of the 1893 stamped envelopes

Billigs Philatelic Handbook Volume 5
Walter Brink's article on the Two Cent Columbian

The Brookman book of 19th Century US Stamps would have something to say about each of the stamps including the 233a Blue error. In fact much of what you may read in auction descriptions can often be attributed to Brookman.

I reccomend you do a digital search of the APRL and any items that interest you the APS staff will photocopy and mail to you for a very modest fee. APRL is the American Philatelic Research Library. My experiences with their services have been very positive.

https://books.google.com/books?id=L...1893&f=false

Beginning on p. 170.

I don't have Scott Specialised, so the answer to that is I don't know.

It was a question rattling asrund in my brain as I have been able to get fantastic handbooks on The Postage Due Stamps of Zanzibar, Queensland to 1912 and a couple of books (Arfken and this year Charles) on US Postage dues.

I was considering a new collecting area and looked at the Columbians as a possibility.

Is there much difference in the detail (ignoring prices, of course) between Scott Specialized of 1970, 1990 and 2010?

Phil Banser looks to have most of the references cited above.

Thanks for the responses, just the info I was looking for.

Wow, what a collection. Much valuable information in the notes too.