That takes me back a bit! One of the first places i ever tried to go explore after seeing it on 'workhouses.org' or some such hideously outdated (but very useful) website.. I never did get in it tho im afraid, not long after i went they built a big modern bit next door and started using it again. Must have been 2005/06 maybe??
'Oaktree manor' it seems to be called now:
(That said looking on google it looks quite deserted again so maybe they have stopped using it for a second time. Sadly tho if thats the case its not been empty for as long as you might think.)