Frosty always post right after an update of the UI when avialable.
You can always find them under the tab on top of the page.
Click downloads then scroll down to the section for lotro and click
the forum topic LotRO Developer Utilities then will give you a list of all the old and the new UI zip pack from Frosty.
Make sure you check the dates before you get the zip,that way you won't download an old release.