1840 Date varieties
I have noticed two minor variations to the 1840 date with the of positioning of the '40'.
I have used the 1840 A pictures as possibly the norm.
1840 A - The 18 & 40 are in a straight line alignment.
1840 AA - I have drawn a line horizontally the base of the numerals of ST 1840 A.
1840 B - The '40' are out of alignment with the '18'. The 4 & 0 are lower.
The 0 is lower and tilts slightly backwards. Notice the alignment with the
wreath leaf to the left of the 0. On 1840 A the 0 is aligned between two leaves.
The '4' is slightly higher than the '0' but still just below the alignment of the
4 of the norm. The '4' also tilts backwards - very slightly.
1840 BB - I have drawn two lines to show the different alignment to ST 1840 A.