Ferranti High Voltage Test Equipment

Hi all, I am in the UK and have a keen interest in high voltage testing. What I am looking for is any information on Ferranti high voltage test equipment ( impulse generators, cascade transformers etc). This company no longer exists and I would be grateful if there are any engineers out there that have used or been involved with any of this equipment, that can provide technical information of any sort regarding it's use, operation or anything at all. I am new to this site and apologise upfront if I am using it for the wrong purpose. Any help or information however small would be most appreciated. Regards, Paul.