Chris,
27-74-05 is in the archives section at
www.race-cars.com and has been there for a few years , called out as ex Opert/ Roos.??
Also , but with no plate number given is Harper/Purley / Crawford.
As the car is fitted with an FG400 Hewland rather than an FT200 it would appear to be a definate ex F2 purpose built car as opposed to an Atlantic built car.
Bryan.