Keep Gallery 1 hotlinks working after Gallery 2 upgrade

G2 URL (optional): http://somniplex.com/gallery
G2 version: 2.2.5 core 1.2.0.7
G1 URL (optional): http://somniplex.com/gallery but renamed to g1 in course of g2 installation/migration per instructions
G1 version: 1.5
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PHP version (e.g. 5.1.6): 5.2.5 apache
PHPInfo Link (see FAQ):
Webserver (e.g. Apache 1.3.33): Apache/1.3.41
Database (e.g. MySql 5.0.32): mysqli 5.0.51a-community
Activated toolkits (e.g. NetPbm, GD): ArchiveUpload, Exif, Getid3, LinkItemToolkit, NetPBM, Thumbnail
Operating system (e.g. Linux): Linux
Browser (e.g. Firefox 2.0): Firefox 3.0 & IE 7

After the upgrade, despite reading & following the instructions closely, our gallery does not resolve old hotlinks to images in the gallery. I used the import option and the url rewrite plug-in is 'on'.

This is an example of an old url which I would like to return to use (http://www.somniplex.com/gallery/albums/FourthofJuly2004/IMG_4795.jpg) but have not been able to accomplish this now that I have upgraded to G2.

Any help would be much appreciated!