meall, did the original-and-dead cubic battery says its a Raytek in red letters?
if so...yeah these are still purchaseable but rather a bit expensive, if you're not the type to have the original 'interior' look preserved you always could just take a 4-AA (or AAA) battery holder and put three...
just thought that I would post that the one from family here isn't even much more noise than just a faint motor humming in a quiet room so humm maybe its a hit and miss thing?