do they have audio outputs and MIDI connectors?
the hammond i play doesn't because again, it's from the 50s/60s. i doubt that later models had it though, because iirc the company didn't last beyond the 90s (though they probably died off before then). the pipe organ i play doesn't have audio outputs that i know of, but it does have some midi settings as well as some sort of data setup where it looks like you can put stuff like floppy drives in it (so that one isn't much older than 2004, at the most). the electric organ for my lessons had optional midi connections (though they cost extra so the college didn't get them) and i'm pretty sure it has an audio output for when the college holds big recitals with the organ.
it really depends on the organ; traditional pipe organs wouldn't come with an audio output because they have forgethuge pipes (the one i play goes up to 32'), but i'm sure that modern ones may have optional midi support. electric organs, depending on the age, would most certainly have some kind of midi functionality (whether or not it's an extra depends on the company, i'd assume), especially if you get the ones that
don't even try to look like a traditional organ console.