What type of toms are these?

I bought some tomato plants earlier this year from a nursery and they were tagged as being plum tomatoes. They were out of a table full of plum ones but im pretty sure they are not what they are supposed to be, the fact they are round gives it away a bit. The thing is, what type are they? Looking in my book they seem like marmande as they are quite big and have the ridges on them,some are a funny shape too, a bit deformed, what can cause this? maybe you can tell better what they are?

 

Could be Marmande or similar, they look more like a Beefsteak tom rather than a plum.

 

They look just like the Amish paste I am growing at the moment.
robert

 

Whats the brown round the stalk? A few of them have it.