You may be familiar the MERLIN database that was released as a Freedom of Information (FOI) act request and holds data on British military vehicles up until around 2013. The information presented here is primarily made up of this dataset, which is also presented on other websites.
However, what makes the data on this site different is that is not just a snapshot; the data here has been updated with data from further FOI requests, sales through disposal agents, as well as being combined with records from the DVLA. The MERLIN database, as released, has many inaccurate VINs in it, which I have researched and fixed to build a better picture of which vehicles are now in private ownership. It also means that military history can be found for vehicles that have had their ERM and miltary plates removed.
Search for a military number plate (ERM)