Some 1907 LC's have an interesting, short lived feature. Five pins on the lock vs. three. This is an early 1907 model (311,75x). Curious if yours is 3 or 5?
I've degreased wood using multiple acetone soaks w/heat. It works well, but is time consuming and potentially dangerous.
Haven't tried aqueous methods such as TSP or detergent. Might be worth a shot.
If the break is clean and isn't missing any pieces, you should be able to make the repair almost undetectable w/epoxy and surgical tubing.