Joe Jarrick is unquestionably the expert on 100S matters so I believe we can assume AHS 3804 did not run in the Mille Miglia
Why does it wear the plate OON 440?
I believe that its because its former owner Fred Hunter believed, rightly or wrongly, that it was the Mille Miglia car.
About 10 years ago when I began my website he sent me the following information about the car for inclusion in the Mille Miglia section
'This car was in fact the older special test car SPL-224B which had recently been refurbished to the specifications of the latest 100S production cars and numbered AHS 3804.
The car had been prepared as a "gift" from Donald Healey to Ed Bussey of Ship and Shore Motors of West Palm Beach, to thank him for all the help he had given the Healeys at Sebring.
Before it could be delivered to Bussey, Healey realised he was going to be short of cars for the 1955 Mille Miglia which was shaping up to be a very exciting race, and so the car was pressed into service with great results. It was painted red and bore the registration number OON 440, that actually belonged to car SPL 257B, which had been damaged in the Carrera Panamerica race.'
I included that info on my site and in fact its still there - I'll have to amend it.
One other interesting point to note re AHS 3804.
In 1957 three Streamlined '100-Sixs' ran at Sebring. These cars had the six cylinder C- series engine fitted and the bodywork was the same as the 1956 Bonneville endurance car. Little concrete info is available about these cars but the feeling is they were based on 100 chassis not 100-Sixs. The entry list for the 1957 race shows one of the cars as being AHS 3804! Could it be that this car was rebodied and re-engined for the race and later in life returned to its 100S form? Interesting stuff.