I originally thought that the only way to identify a small size replacement note was by the serial numbers being 'crooked' or having a definate upward or downward tilt.
There is an article on Series 1929 National Bank Replacement Notes in the March/April, 2012 issue of Paper Money. On page 98 of the article, there is a diagram showing the critical diagnostic alignment within the brown overprints on Type 1 National Bank Notes.
I made a transparent overlay using a random Type-1 NBN from my collection (hoping that it would be a regular issue note). I then used this overlay to examine my other notes.
I scanned the notes that were off (either significantly or just barely). Those scans are shown below.
My questions are:
1. How far off does the alignment have to be before it is an unquestionable replacement?
2. Which, if any, of the notes shown are replacement notes?
3. Will the third party graders (either PMG or PCGS) label them as replacement notes?