Maltese Cross Wincanton No Dot

I can't find any info on this Wincanton Maltese Cross Cancel... All I find have a dot in one of the corners... Am I missing something?

Hi; From what I gathered The Wincanton dot cross is quiet rare actually on dated covers.
It was used only up too January 22 1842?The others are the standard cancels?


http://www.philatelicsannex.org/ref...ostmarks.pdf
lot;627
http://www.grosvenorauctions.com/PD..._527_649.pdf

Thanks perf12 for the info & the links..

To summarize the pages in the Encyclopaedia of the Maltese Cross by Rockoff and Jackson:

They list 13 dated Wincanton covers from 9 June 1840 to 2 Oct 1843
3 of them have dots in the outer loop of the MX - 17 and 22 Jan 1842 and 23 July 1843.
The others don't have the dot.

They hypothesize that the dot was caused by foreign matter adhering to the obliterator.
Two of the covers were 5 days apart. Then there is a cover without the dots, implying the device was cleaned.
The dot in the cross a year later appears to be a different size and shape from the earlier dots.

Hope this helps.
Chip

Thanks chipg for the info.. I know now for sure..