I have a 16S 21 jewel Hampden N0.105, model 5,S.N. 3394408.It has an original porcelain DS Montgomery dial which has something unusual about it.I can't post a picture of it, but the odd thing about it is, the minute marks at one minute before and after the 12, that is the 59 and 1 minute marks,have an extra line in between, as if to show a 30 second mark.I have never seen that before, have seen other Hampden Montgomery dials, and none have the extra 30 second marks.Would anyone care to guess why that was done, or ever seen another one like that?Another Hampden mystery I iguess.Thank you in advance, Ted.