Hi Al
The markings are for the RAF Regiment (armoured car squadron as it was in 1941) and this actual car is preserved in the RAF Regiment museum and searchable on the 'net.
The roundel is an air recognition marking, and all RAF armoured cars of this era were named instead of being numbered.
It's a fairly easy build apart from the rear suspension, which fouls on the exhaust - fit the axle/springs first and then if necessary cut'n'shut the exhaust around it. There is a basic interior to the car, with just seats, steering wheel and pedals with three .303 enfields that can be posed, but no racks for them. Apart from a basic breech for the MG, ammo can and seat there is no detail inside the turret so a lot of scratch building will be required if the hatches are to be left open.