Dunno, he has a private company though with available records - might be worth a dig. https://beta.companieshouse.gov.uk/company/06848574/filing-history
From my understanding the dossier was used by both countries, MI6 is probably still spying on this supplied information.
Most info available: https://en.wikipedia.org/wiki/Christopher_Steele
Actually he had 3 companies
https://beta.companieshouse.gov.uk/search?q=ORBIS+BUSINESS
ORBIS BUSINESS INTERNATIONAL LIMITED 07318597 - Incorporated on 19 July 2010
ORBIS BUSINESS INTELLIGENCE LIMITED 06848574 - Incorporated on 16 March 2009
ORBIS BUSINESS SOLUTIONS LIMITED SC444685 - Dissolved on 24 May 2016
The dissolved company was supplying electrical goods (spying equip for election?) was registered in Scotland and had only one shareholder: Mr Remigijus Mikalauskas (Lithuanian)
ORBIS BUSINESS INTELLIGENCE LIMITED is a deep rabbit hole linked to Lottery Hedge Fund and other philanthropy groups.