There is a fix, but you're not going to like it.
ONLY do this if you desperately want Update 1.
Download and install Nokia Software Updater for Retail 4.1.2 and connect your phone.
Click Install and tick the precaution warning box.
Let the firmware download and install, DO NOT REMOVE THE USB CABLE.
Once stock firmware is installed, update OTA with all available updates BEFORE Preview for Developers.
If there are no updates, install Preview for Developers and do all the updates.
You should have Update 1 after all PfD updates.
It worked for me on a Nokia Lumia 630 CV GBIE & confirmed working on 13 other devices including L920, L925 & L520.