Grading Franklin Halves

I sometimes have a hard time grading Franklin halves to determine AU vs. uncirculated.

Here is the problem. Most grading guides (ANA, Photograde, etc.) suggest looking for wear in certain spots - the lettering on the bell and the ropes it hangs from, hair on the obverse, bell lines, etc. The problem is, these are the exact same things that other guides (PCGS, Ehrmantraut's book, etc.) suggest looking at to determine full strike since they tend to vary. Combine the inconsistent striking of high wear areas with the ease with which Franklin halves can be dressed up, and it can become hard to identify a true mint state coin.

Is the bell lettering indistinct because of wear or strike? That's the problem.

Are there any features I should be looking at, which are consistently struck across all years and mints, which I can use to definitely confirm lack of wear?