2 more things that take little time and work, and that have no affect on functioning...
1. Change the screw that holds the cock onto the tumbler. Replace the flat/faceted Siler screw for one that's domed... or domed with a flange.
2. The underside of the pan has a flange. You can use a small round file to change it from convex to concave.
Along with reshaping the frizzen spring finial, none of these is radical, they take little time and work, and they make a Siler less obvious. In fact, if you took a rifle to a show or shoot with a Siler lock modified in this way, I'd bet money at least one person will ask the question... "what lock did you use".
I wish there was a way to change the look of the frizzen. That deep hollow cut where the back side of the frizzen face meets the pan cover is a big giveaway. People try to reshape it by grinding, but you can never get rid of that recess completely. You'd have to remove too much metal (in my opinion) to really make a difference. As mentioned above, Track of the Wolf used to sell parts (including a frizzen), but I don't think they have been available for a long time.