Hi - I yanked some parts from an old APC unit - a 350 (I think). A chunky transformer has markings of LEI-4, 430-2020 and also 155D. Think this think is worth keeping? Thing weighs about 3 lbs.
I did find posts on measuring various aspects of unknown transformers but I think I'll leave that till I have some more comfort with what I'm doing.
H. Dixon