currently upgrading form 1.39 to 1.5.1

SIMPLE SEO URL is not supported in 1.5.1. However, as most other Zenners know the BIG problem with installing the ULTIMATE SEO URL mod is we will lose all the page URLs currently indexed by Google. a BIG problem . Is there anyway around this, i.e. to maintain current URLs set by SIMPLE SEO URL ? I know there is a paid mod that supposedly redirects the old Simple SEO URLs