Tim, how could we forget BEX 1054.....but I was talking AC engined cars which have always been a bit under the price radar for the Bristols.
The point about the MM retrospective is interesting because as many will know there are a lot of, sometimes quite ordinary, or totally obscure, cars eligible. This list shows 173 makes and 902 models!!!
http://www.1000miglia.eu/attach/Content/Interna/2176/o/19271957elencovetturepartecipantienglish19_11_2015.pdf So theres quite a choice around... In UK terms things like early TR2/3, MGA etc all qualify, so there are a lot cheaper ways of getting an eligible car; however getting an entry is another matter. Its worth just glancing down the list to see how many makes are there you've never heard of! A Picon, a Platé, a Pulidori just in part of one section, for example...
There is at least one Ace I know of in this year's event, Paolo Pedersoli in AEX 100, a car which originally was sold to Canada. Good luck to him in the event.