I would say it depends on what you're trying to accomplish.
If you're making a copy, you better stick pretty close to the original.
If you're making an interpretation, I guess you have more leeway. However, if you're going to correct things that don't agree to your eye, first be sure that what you're correcting isn't one of the makers distinguishing traits.
Some of those traits might be obvious, and some not so much.
An obvious trait might be having the patchbox release on the butt plate. Moving it to the toe might not be a good idea. A not so obvious trait might be the shape and details of the trigger. Should you change it just because you don't like it?
A lot of makers had little things that they used over and over, and might be noticed if they're missing.
Sometimes guys post a gun here that they made, introducing it as his such and such.
I, and I'm sure others here look at it and think, well no its not, because it doesn't have that makers traits. But I also have to say that it also makes a difference in how you introduce it. As a copy. As your interpretation. Or this is the way I wish Jacob Dickert had made his rifles!
In the end, it's your gun and you're going to make what you want it to be, so like I said at the start, its what your trying to accomplish with the gun.
John