Hudson seems tempting as "uncommon eng" seem to have kept the development going when others stopped. I would like a Mopar 265 but have not seen one here in Australia, though they probably exist. The most common flathead six is the Dodge 250, this was available till 1962 I believe in the local Chrysler Royal.
The other engine that does not exist is the Ford flathead six, all our Fords were V8, till the British Zephyrs came along. This is a pity as they seem to be 12 port, by pictures I have seen on the net.All the others like Pontiac, Olds, Studebaker or Continental are here but don't seem to offer any advantage over the Dodge. If I was going straight 8 I would look for A Packard Super 8, these seem to be the best of the flatty's. That is why I was curious about the Packard 110 six, is it 3 port or like it's big brother two ports per cylinder, Can any Packard lover tell me?