I thought the "rail dial" referred to the two lines for
Superlative chronometer
Officially certified
Where the gap betweens both words on each lines were perfectly align in the middle.
See for more about "rail dials"
>>>
http://www.doubleredseadweller.com/rail_white_sd.htm on the excellent DRSD website
>>>
http://www.newturfers.com/vb/showthread.php?t=2256 on TRF
;-)