It is of course quite possible that the way a piece of Monart is finished could relate to the shape being made, just as much as its chronology. Maybe this should be bourne in mind?
With further research into Monart bases and pontil marks, I have come to the conclusion that a particular Monart shape does not determine what type of base and pontil mark is used on said piece.
The link below shows a selection of various Monart shapes with a variety of bases and pontil marks.http://glassgallery.yobunny.org.uk/thumbnails.php?album=991
The first two images are Monart shape AE, the next three are shape A, next two shape FA, next three shape FB, next two shape RB, next two shape WK, the next two shape WH and the last two shape Z.
As can be seen the shape of the piece does not determine the type of base and pontil mark finish.
Frank Andrews touched on the subject of dating a piece of Monart by the base and pontil mark (http://www.glassmessages.com/index.php/topic,3692.msg29304.html#msg29304
), my conclusion are, in the main the type of finish of the base and pontil mark on a piece can be put in chronological order. I believe the first type of finished used by Monart was, no grinding to the base and some grinding on the pontil mark, see shape A,FB and Z with Monart Ware label, the second was with a polished base and some grinding to pontil mark, see shape FB with pre war Monart Glass label and the third was polished base and pontil mark, see shape Z with post war Monart Glass label.
There is two other types base and pontil mark finish, one has the base polished and a concaved pontil mark and the other is when a piece has been polished completely flat with the pontil mark polished out, these two type of finishes were used throughout the life span of Monart. These can be seen on shape WH in link to glassgallery.
My research is still ongoing, if any members have a Monart piece with different type of finish other than I have described, please let me know.