There are Marlin Elsies from the 40's and Marlin Elsies from the 70's. I have a 1947 Marlin Elsie 12ga field grade and there is nothing wrong with it, other than being kind of plain. I think that is a much better choice than one of the 70's guns, and should hold more of its value. Found mine on the rack at one of the local black gun stores. Same chain, different store, found an Ideal Grade 16 Featherweight with 30" barrels in very nice condition at a very nice price. Bought my Crown Grade 12 after my cousin yelled across a dove field, "Hey, do you like LC Smiths?" Wasn't actively looking for any of them, but they are where you find them. Just keep poking around in nooks and crannies. I think the Ideal is one of the nicest models, and not terribly pricey in 12 ga.
