If you do go for the ovals, then it should be trivial to arrange to use the same paint package and make an oval shape maybe half as high as wide (or take one of the circles, as given, and make any vertical pair with a dot into a single Z).
From the look of andyman's oval, it was done by something very similar to centre-of-brick, without regard of whether the brick is wide or narrow (see how the mid-level extremities are 'rough', although they would be rougher if the long-bricks were included in the outer), so just ignore the brick sizes in that image, treat the wide/narrow/wide sequence in a column as just a plain column of square tiles and you get something like the following:
##################################################
###############...................################
###########............................###########
########..................................########
######......................................######
####..........................................####
###............................................###
##..............................................##
?................................................?
#................................................#
..................................................
Note that it is also slightly asymmetrical in the original, so I suggest you choose one side or the other of the curve (whichever you find nicer) and mirror it. Also, in the proportional font of this text entry window, the RHS "inner curve" almost lines up vertically with the comparitive size of "#" and "." characters. Perhaps if you made it line up (then looked at it again in non-proportional font) it would look even better, for an obscure font-size reason that is doubtless purely coincidental to the problem at hand.