Most of the questions here are "my current car is broken?".

Well, yes, they're going to be: http://mechanics.stackexchange.com/help/on-topic

"What are the key differences between a model A and Model T ford?"

An open-ended question like this is hard to answer definitively. For example, what makes a difference "key"?

A more specific (and yet still "historical) question could be answered however. For example, if you were to ask "I can't seem to get a good oil seal on my Model A - were they always known to have poor oil seals?" (a problem similar to one faced by my neighbor: his vintage car was always known for poor oil seals so he has drip pans everywhere).

The chat room, however, has fewer restrictions and is a perfect place to bring up conversational topics or questions.

Most of the questions here are "my current car is broken?".

Well, yes, they're going to be: https://mechanics.stackexchange.com/help/on-topic

"What are the key differences between a model A and Model T ford?"

An open-ended question like this is hard to answer definitively. For example, what makes a difference "key"?

A more specific (and yet still "historical) question could be answered however. For example, if you were to ask "I can't seem to get a good oil seal on my Model A - were they always known to have poor oil seals?" (a problem similar to one faced by my neighbor: his vintage car was always known for poor oil seals so he has drip pans everywhere).

The chat room, however, has fewer restrictions and is a perfect place to bring up conversational topics or questions.