The initial bug summary was mistaken.

It is easy to tell whether an edit was imported from the Nostalgia Wikipedia because it's revision ID (the number at the end of the URL, obtained by clicking on the timestamp in the user contributions) is more than 330,000,000, since it would have been imported in December 2009 or later. All the edits that were left behind in the rename of User:Blake have revision IDs between 250,000 and 300,000, indicating that they were imported in September 2002 by Brion's mass-import script.

The edits that were left behind in the user rename have one thing in common: the user ID recorded in the database for the user who made the edit (i.e. the rev_user field) for all the edits is 0, much like edits made by unregistered users. This occurred because there was no user by the name of "Blake" when the UseModWiki edits were mass-imported in September 2002. The user ID for a specific edit is always 0 when there is no "contribs" link for that user when viewing the edit. See principle 8 of:
http://en.wikipedia.org/wiki/User:Graham87/Import

In fact, the only edit imported from the Nostalgia Wikipedia did move when Blake was renamed. See:
http://en.wikipedia.org/wiki/Special:Contributions/Blake_(usurped)

and note the edit's revision ID of 394,985,529. I have just imported two edits from the Nostalgia Wikipedia that were made by User:Blake, to the articles "Gray coding" and "Two stroke cycle". Fiddling with usernames from the UseModWiki era generally makes my job harder; see the last bullet point in the section about "Overlapping edits and mismatched titles" in my page about importing edits from the Nostalgia Wikipedia (linked above). However it's not much of a big deal in this case because User:Blake has only six edits in the Nostalgia Wikipedia database.

The principle referred to above in comment 1 is now principle #9 of my user subpage about importing edits from the Nostalgia Wikipedia.

bwsalveson wrote:

So can these edits be moved to the old user? It is weird with me having edits from 2001 when I started editing in 2008. (I am the new "Blake")

Yes, but a Wikimedia sysadmin will have to do it. If a bureaucrat renamed your account, the two edits that I imported to the "Gray coding" and Two stroke cycle would be attributed to you, but the other three edits from 2001 would still be attributed to the username "Blake".

If I hadn't done the import yesterday, a bureaucrat could have completely removed the 2001 edits from your contributions by renaming your account a second time, then maybe renaming "Blake (usurped)" back to Blake. Oops! Maybe it is possible to delete the imported edits, rename your account, then re-import them, but that's clunky.

bwsalveson wrote:

Could they maybe be moved to a completely unrelated account? "Blake(old)" or something. If not, then it isn't a problem, and you don't need to go through too much trouble. It is just odd looking [http://toolserver.org/~soxred93/ec/Blake here] and there is a long area of no editing. I guess this is why users generally aren't usurped if they have made edits. :<

Nope, not without contacting a sysadmin:
http://meta.wikimedia.org/wiki/System_administrators

If there were no edits from the UseModWiki ear of Wikipedia (e.g. before 25 January 2002), there wouldn't have been a problem with the usurpation.

tim.starling wrote:

content hidden as private in Bugzilla

content hidden as private in Bugzilla

john wrote:

content hidden as private in Bugzilla

(hit comments 7, 8, 9 related to spam).

Is this issue possibly a duplicate of bug 27873?

Nope, I don't think so, as this bug almost exclusively affects editors who edited in the UseModWiki era of Wikipedia.