Not to throw any more cold water on this particular idea, but there are at least two more things to consider.
1) Outside of the connection to Bonham, this rail is completely disconnected in Paris and the crossing south of town has been removed. Thus, unless you make some sort of agreement with the railroad in town, you will have no way to get your trains into town and to the depots or anything else. Without that sort of an agreement in place, you cannot go forward.
2) In the comments about motive power, 400 at Marshall was mentioned as was the 316 at Palestine. 400 is owned by the city of Marshall, and 316 by the cities of Palestine and Rusk. It will take some tall talking to make them give up something that they own especially in the case of the 316, to someone who is in direct competition with them for their tourist dollars.